Title of Invention	"A METHOD FOR PREPARATION OF X-CARRAGEENASE"
Abstract	The present invention relates to a method for the preparation of K-carrageenase. More particularly, the present invention relates to a method for the preparation of K-carrageenase by using halotolerant marine gram negative bacteria Pseudomonas sp. with accession number MTCC 5261. Halophilic marine gram negative bacteria, isolated from decayed algae, hydrolyzed K-carrageenan. To maximize K -carrageenase production in the cost effective manner, a novel medium was defined having minimum components and their optimum concentration by statistical optimization method. Hence there evolved a novel medium composition for enhanced K -carrageenase production by a new halotolerant marine bacterium, Pseudomonas spp.

Title of Invention

"A METHOD FOR PREPARATION OF X-CARRAGEENASE"

Abstract

The present invention relates to a method for the preparation of K-carrageenase. More particularly, the present invention relates to a method for the preparation of K-carrageenase by using halotolerant marine gram negative bacteria Pseudomonas sp. with accession number MTCC 5261. Halophilic marine gram negative bacteria, isolated from decayed algae, hydrolyzed K-carrageenan. To maximize K -carrageenase production in the cost effective manner, a novel medium was defined having minimum components and their optimum concentration by statistical optimization method. Hence there evolved a novel medium composition for enhanced K -carrageenase production by a new halotolerant marine bacterium, Pseudomonas spp.

Full Text	A METHOD FOR THE PREPARATION OF K-CARRAGEENASE Field of invention: The present invention relates to a method for the preparation of K-carrageenase. More particularly, the present invention relates to a method for the preparation of K-carrageenase by using halotolerant marine gram negative bacteria Pseudomonas sp. with accession number MTCC 5261. Background and prior art of the invention: The potential uses of K- carrageenase is to obtain low molecular weight carbohydrates, for kelp digestion, for prevention of biofouling by controlling red algal bloom formation, to obtain fine chemicals and for algal biotechnology. Carrageenan is a natural ingredient obtained from certain species of the red seaweed; class Rhodophyceae (Greer, C.W., and W. Yaphe.1984. Enaymatic analysis of carrageenans: Structure of carrageenan from Eucheuma nudum. Hydrobiologia. 116/117: 563-567). Carrageenan is a linear polysaccharide made up of repeating dissacharide sequence of 1,3 linked P-D-galactopyranose called the A residue and a-D-galactopyranose residues linked through positions 1,4 called the B residue. Carrageenans are distinguished from agars in that the B units in carrageenan are in the D form whereas they are in the L form in agar. The regular backbone of the basic structure of carrageenan is disrupted by a more or less ordered distribution of sulfate hemi ester groups. Carrageenan can also contain some methoxy and pyruvate groups. Popular sources for carrageenan are Chondrus, Eucheuma (Kappaphycus), Gigartina and Iridaea species. Three basic types of carrageenan are available. Kappa (K), iota (i) and lambda (A,) carrageenan which are obtained from Chondrus, Eucheuma and Gigartina species, which differ in the number and location of sulfate ester substitution, K and i-carrageenan form thermally reversible gels in the presence of K+, Ca+2 or NH4+ but do not gel in the Na+ form. Hydrolases, which degrade carrageenans at P-1,4 linkages, are known as carrageenases. Three types of enzymes, viz. K, I and λ,-carrageenases, have been isolated from various marine bacteria. They all are endohydrolases that cleave the P-1,4 linkages of carrageenans yielding products of the neocarrabiose series (Michel, G., L. Chantlat, E. Fanchon, B. Henrissat, B. Kloareg, and O. Didweberg. 2001. The i- carrageenase of Alteromonas fords. Journal of Biological Chemistry. 276(43): 40202-40209). K-carrageenase has large-scale application and industrial demand in the forth-coming years (Ostgaard, K., B.F. Wangen, S.H. Knutsen, and I.M. Aasen. 1993. Large scale production and purification of K-carrageenase from Pseudomonas carrageenovora for applications in seaweed biotechnology. Enzyme and Microbial Technology. 15(4): 326-333). Jhonston and McCandless in a paper entitled "Enzymic hydrolysis of the potassium chloride soluble fraction of carrageenan: properties of λ,-carrageenases from -Pseudomonas carrageenovora" in Canadian Journal of Microbiology 19: (1973) p.p.779-788, has reported that carrageenase from Pseudomonas carrageenovora exhibited activity only against KCl soluble fraction of carrageenan i.e. λ,-carrageenan. They could improve the yield of λ- carrageenase but could not totally eliminate simultaneous production of K-carrageenase. Also, after using multiple and complicated steps of purification, specific activity achieved was only 7 galactose units/mg protein which had temperature and pH optima 28°C and 6.2 respectively. The drawback of this work is that carrageenase is active only in acidic condition and at 28°C temperature. Hence it can not be used in alkaline condition as well as at elevated temperature. Moreover, the process did not yield noteworthy purification of enzyme, inspite of using complicated enzyme purification steps. Bellion et al. in a paper entitled "The degradation of Eucheuma spinosum and Eucheuma cottoni carrageenans by i and K-carrageenases from marine bacteria" in Canadian Journal of Microbiology 28(7): (1982) p.p. 874-880 has reported the degradation oi Eucheuma spinosum and Eucheuma cottonii carrageenans by i-carrageenase and K-carrageenase from marine Pseudomonas carrageenovora and identified the hydrolyzed products. The bacterium was cultivated in a medium consisting of g. l-1 NaCl 25; K2HPO4 0.1; MgSO4 7H2O 5.0; CaCl2H2O 0.2; casamino acids 2.5; carrageenan 2.5; 0.3 % FeSO4 (l0ml/lit) and optimum incubation temperature of 22°C. The drawback is that the medium used for the production of carrageenase by this bacterium consisted of 7 components. Moreover, optimum incubation temperature used was 22°C, which is not feasible for the cultivation of this type of bacteria in temperate countries without cooling device especially in summer. Sarwar et al. in a paper entitled "Potentiality of artificial sea water salts for the production of carrageenase by a marine Cytophaga species" in Microbiology and Immunology. 29(5): (1985) p.p.405-411 and "Purification of a K-carrageenase from marine Cytophaga species" in Microbiology and Immunology. 31(9): (1987) p.p. 869-877 wherein, 8 components were used in the medium for the production of carrageenase by a marine Cytophaga sp. Moreover, this culture required a suitable combination of NaCl and MgCl2 for carrageenase production. The pH and temperature optima were 7.6 and 25°C respectively. The activity achieved after following complicated steps of purification was only 5.0 galactose units/ mg protein. The drawback of this work is that the presence of NaCl and MgCl2 in the medium is a must for carrageenase production and inspite of using eight medium components and complicated steps of purification; only 5.0 galactose units/ mg protein was obtained as enzyme activity. This low yield makes the enzyme production commercially uneconomical. Fleurence et al. in a paper entitled "Use of enzymatic cell wall degradation for improvement of protein extraction from Chondrus crispus, Gracilaria verrucosa and Falmaria palmata" in Journal of Applied Phycology 7: (1995) 393-397) wherein, K-carrageenase was reported to have maximum activity between pH 6.5-6.8 and at 45°C and lower activity at acidic and alkaline conditions. The drawback of this work is that the enzyme is active only at neutral pH hence can not be used either in acidic and alkaline conditions. Moreover, poor activity at lower temperature makes its applicability limited to higher temperature . Dyrset et al. in a paper entitled "Development of a fermentation process for production of a K-carrageenase from Pseudomonas carrageenovora" in Enzyme and Microbial Technology 20(6): (1997) p.p. 418-423 has reported a fermentation process for the production of K-carrageenase using two strains of Pseudomonas carrageenovora. The medium used for this study contained gl'of CaCl2, 2H2O 0.2; Casamino acid 6.8; KCl 0.3; K2HPO43.0; MgSO4, 7H2O 0.5; NaCl 20.0; NH4CI 0.7; (NH4)2 SO4 5.0; Carrageenan 2.5. The pH of the medium was 7.0 and temperature was 20°C. The drawback of this work is that large number of components as well as high substrate concentration is required in the medium and the maintenance of pH 7.0 with all these components is difficult. Besides, the fermentation process is carried out at 20°C, which requires special device for maintaining such low temperature Araki et al. in a paper entitled "Purification and characterization of K-carrageenase form a marine bacterium Vibrio sp. CA-, 1004" in Fisheries Science 65 (6): (1999) p.p. 937-942 wherein, they purified and characterized K-carrageenase, an inducible enzyme, from a marine bacterium Vibrio species, the molecular weight of which was 35 KDa and maximum enzyme activity at pH 8.0 and temperature 40°C. The medium used for this study contained g r'of peptone 5.0; yeast extract 1.0; NaCl 30; MgSO4 0.5; K2HPO4 2.0; KH2PO4 0.4; carrageenan 15. The activity of crude carrageenase obtained was 0.949 galactose units/ mg protein. The drawback of this work is that production medium containing seven components yielded carrageenase with activity of only 0.949 galactose units/mg protein. Such low activity would invariably make the process uneconomical and unfeasible. Japanese patent No. JP2001136961 (2001) assigned to Okita Yuji et al. has disclosed a "Method for controlling carrageenase producing ability of bacterium" is described. Here, a method has been described to control the carrageenase producing ability of a carrageenase producing bacterium, by culturing it in the presence of a bacterium free from the carrageenase producing ability or its culture product. The drawback of this invention is that production of carrageenase was controlled only by co-cultivating carrageenase producer with that of carrageenase non producer. Japanese patent No. JP 2000116376 (2000) assigned to Araki Toshiyoshi entitled "New K- carrageenase, microorganism for producing the same, production of carrageenase and its use" has disclosed that K- carrageenase has decomposition activity against K-carrageenan. This enzyme decomposed K-carrageenan into neocarrabiose and neocarratetraose and had pH optima of 8.0. The drawback of this invention is that the enzyme had only alkaline pH optima hence can not be used in acidic condition. Japanese patent No. JP 1006656 (1998) assigned to Christian G et al. entitled "Production of K- carrageenase" has disclosed the productivity of K-carrageenase by Pseudomonas carrageenovora, Alteromonas or Cytophoga which was substantially improved by controlling the pH of a culture medium by nitrogen containing base (ammonium water) to be assimilated by these bacteria. By this, K-carrageenase production could be improved from >= 20 galactose Units/ml to 40 to 60 galactose Units/ml. The drawback of this invention is that they could achieve only 3 fold purification after controlling pH which is not viable commercially. Canadian Patent No. CN1544623 (2004) assigned to Haigin M et al. entitled "Carrageenin catabolic enzymes it's preparing process and application", wherein, an enzyme that can degrade K-carrageenan to prepare oligocarrageenan and degrade beta-1,4 indican bond of K-carrageenan having a molecular weight of 30KDa was obtained. Cytophaga sp. was cultured at 28-35 deg. C, centrifuged to obtain crude enzyme and concentrated it by using 40-80% ammonium sulphate. This method was compared with chemical method; it had simple preparing course, high product yield, and stable quality and ensure the activity research and development of oligosaccharide etc. The drawback of the present invention is that only salting out method was used for concentrating enzyme which does not give substantially concentrated /purified enzyme preparation. Objects of the invention: The main object of the present invention is to provide a method for the preparation of K- carrageenase. Another object of the present invention is to provide a method for the preparation of K- carrageenase by using halotolerant marine gram negative bacteria. Further another object of the present invention is to provide an improved K- carrageenase by using halotolerant marine gram negative bacteria which grows in a novel medium composition with optimum concentration. Yet another object of the present invention is to maximize carrageenase production in a simple manner involving less complicated techniques. Yet another object of the present invention is to provide K- carrageenase having excellent K- carrageenan hydrolyzing activity. Yet another object of the present investigation is to obtain K- carrageenase having activity in alkaline and acidic conditions. Yet another object of the present investigation is to obtain K- carrageenase having higher temperature stability. Yet another object of the present investigation is to obtain K- carrageenase having high substrate specificity. Yet another object of the present investigation is to obtain K- carrageenase having prolonged storage stability. Yet another object of the present investigation is to obtain K- carrageenase having high substrate specificity. Yet another object of the present investigation is to obtain K- carrageenase having prolonged storage stability. Yet another object of the present investigation is to obtain K- carrageenase having capability to generate protoplast of Kappaphycus alvarezii. Summary of the invention: The present invention deals with a novel halotolerant marine bacterium, Pseudomonas spp. with accession no MTCC 5261 useful for the production of high activity K-carrageenase. In order to maximize K-carrageenase production in a simple manner, a new medium composition is defined having minimum components and their optimum concentration using statistical optimization method to reduce number of experiments, save time and chemicals and to improve higher authenticity of the results by observing combined effect of all the factors influencing enzyme production. Detailed description of the invention: Accordingly, the present invention provides a method for the preparation of K- carrageenase, wherein the said method comprising the steps of: (i) isolating the bacterial culture from decayed carrageenophyte by growing it in a culture medium containing carrageenan as the only carbon source; (ii) cultivating the bacterium in an statistically optimized liquid medium containing components in the concentration range of (g 100ml-1) a) carrageenan 0.001-3.0; b) yeast extract 0.01-1.0; c) sodium chloride 0.5-15.0; d) K2HPO4 0.01-0.5; e) KH2PO4 0.005-0.05, on a rotary shaker for a period in the range of 16-72 hours and temperature in the range of 15-50°C; (iii) centrifuging the culture suspension in the range of 5000-8000 rpm for a period in the range of 20-40 min and obtaining cell free extract as supernatant and discarding the settled pellets; (iv) purifying the crude enzyme (supernatant) containing unwanted impurities other than K- carrageenase by treating with ammonium sulphate in the concentration range of 20- 80% (wt/vol) at a temperature in the range of 3-15°C and aging the mixture for a period in the range of 12-36 hours; (v) centrifuging the mixture obtained in step (iv) in the range of 5000-8000rpm and at a temperature in the range of 3-15°C to obtain pellets of precipitated protein and discarding the supernatant; (vi) re-suspending the pellets obtained in step (v) in Tris- HC1 buffer solution of concentration in the range of 10-30 Mm; (vii) dialyzing the suspension obtained in step (vii) for removing the adhered ammonium sulphate against the same buffer; (viii) further purifying the partially purified enzyme using gel filtration technique to obtain desired purified K-carrageenase. In an embodiment of the present invention, the said bacterium, Pseudomonas sp have the following characteristics: a) halophilic; b) gram negative, exhibits gram variability; c) motile aerobic rods; d) it degrades algal polysaccharide i.e. K- carrageenan. In another embodiment of the present invention, the said K- carrageenase is purified using gel filtration technique on Sepharose CL-4B. Further, in another embodiment of the present invention, the specific activity of said K- carrageenase is in the range of 10- 200 galactose units / mg protein. Yet in another embodiment of the present invention, the said K- carrageenase have the molecular weight 128KDa. Still in another embodiment of the present invention, the said K- carrageenase have excellent K- carrageenanse hydrolyzing activity. Still in another embodiment of the present invention, the said K- carrageenase have activity in alkaline and acidic conditions. Still in another embodiment of the present invention, the said K- carrageenase have higher temperature stability. Still in another embodiment of the present invention, the said K- carrageenase have high substrate specificity. substrate specificity. Still in another embodiment of the present invention, the said K- carrageenase have prolonged storage stability. Still in another embodiment of the present invention, K- carrageenase having capability to generate protoplast of Kappaphycus alvarezii The present invention provides a process for improved K-carrageenase production and method for preparation thereof which comprises of the isolation of marine bacterial cultures from seawater and sediment located in the vicinity of red algae and decayed carrageenophyte. These bacteria were grown on a solid culture medium containing carrageenan as the only carbon source. Bacterial colonies producing pits or holes in the above said solid medium were further purified and the bacterium producing maximum depression was selected for further studies. The purified bacterium was then inoculated in a liquid medium containing components in the concentration preferably in range of (g lOOml"') (i) carrageenan 0.005-6.0 (ii) yeast extract 0.0051-3.0 (iii) sodium chloride 0.1-20.0 (iv) K2HPO4 0.001-1.5 (v) KH2PO4 0.001-0.1 for its cultivation. The inoculated liquid culture medium was incubated on a rotary shaker for a period in the range of 12-90 hours and temperature in the range of 10-60°C for production of K-carrageenase. The cultivated culture suspension was then centrifuging preferably in the range of 4000-10000 rpm for a period in the range of 20-70 minutes to obtain crude extracellular K-carrageenase as supernatant (cell free extract). The extracellular crude enzyme (supernatant) was then partially purified by salting out method, using preferably ammonium sulfate in the concentration range of 10-100% (wt/ vol) and at a temperature in the range of 3-10°C and aging the mixture for a period in the range of 12-36 hours to eliminate majority of unwanted protein impurities. This suspension containing ammonium sulfate precipitated proteins was centrifuged preferably in the range of 4000-l0000rpm and at a temperature in the range of 3-10°C to obtain pellets containing mainly K- carrageenase and discarding the supernatant containing other protein impurities. The pellets obtained by centrifugation (containing mainly K-carrageenase) were re suspended in minimum volume of preferably 5-40 mM Tris HCl buffer solution. For the removal of excess ammonium sulfate and other low molecular weight impurities including proteins the partially purified K- carrageenase solution was dialyzed against 0.02 mM Tris HCl buffer using dialysis bag having 12,000 molecular weight cutoffs. For further purification of ammonium sulfate precipitated K- carrageenase, gel filtration technique on Sepharose CL-4B was used and K- carrageenase rich fractions were recovered by eluting them using Tris HCl buffer preferably in the concentration range of 5-50mM. The molecular weight of purified K- carrageenase fraction was determined by repeated gel filtration method, noting its elution volume (Ve), calculating its Ve/Vo (Vo is void volume of the column) and comparing it with a plot of log of molecular weight Vs Ve/Vo of standard molecular weight proteins markers. Potential uses of this enzyme are as follows: • To improve the physical properties of polysaccharides, conversion to oligosaccharide may be the best choice. The enzymatic degradation of carrageenan yields novel products with high bioactivity. • The enzymes produced by marine bacteria could effectively control red algal bloom contamination. Thus, it prevents bio fouling of submerged marine surface or pipes by acting on complex polysaccharide layers. • These enzymes are essential tools to study structure and assembly of red algal cell walls (Gall, Y. L., J.P.Braud and B. Kloareg. 1990. Protoplast production in Chondrus crispus gametophytes (Gigartinales, Rhodophyta). Plant Cell Reports. 8: 582-585). • These enzymes are useful for kelp digestion (Sarwar, G., H. Oda, T. Sakata, and D. Kakimoto. 1985. Potentiality of artificial sea water salts for the production of carrageenase by a marine Cytophaga species. Microbiology Immunology. 29(5): 405-411). The digested products in turn can be used as carbon source for the growth of bacteria. They are also used for the extraction of fine chemicals from these algae. • Most red seaweed possesses high level of proteins (10-30% dry weight) (Morgan, C, J.L.C. Wright and J. Simpson. 1980. Review of chemical constituents of the red alga Palmaria palmate (dulse). Economic Botany. 34: 27-50; Mabeau, S., and J. Fleurence. 1993. Seaweed in food products: biochemical and nutritional aspects. Trends Foods Science & Technology. 4: 103-107). These proteins can be extracted by hydrolytic enzymes like carrageenase (Fleurence, J., L. Massiani, O. Guyader, and S. Mabeau.1995. Use of enzymatic cell wall degradation for improvement of protein extraction from Chondrus crispus, Gracilaria verrucosa and Palmaria palmate. Journal of Applied Phycology. 7: 393-397). For example, the degradation of cell wall polysaccharides by hydrolytic enzymes is used for the isolation of extensin, a protein linked to cell wall polysaccharide of higher plants (Lamport, D.T.A.1969. The isolation and partial characterization of hydrodyproline rich glycolipides obtained by enzymic degradation on primary cell walls. Biochemistry. 3: 1155-1163). • They can be used for the isolation of protoplast, which can be used for genetic engineering experiments for the production of improved algal strains (Chen, L.C.M., J.S. Craigie, and Z.K. Xie. 1994. Protoplast production from Porphyra linearis using a simplified agarase procedure capable of commercial application. Journal of Applied Phycology. 6: 35-39). • They are used in molecular biology to prevent severe separation problems occurring in the presence of phycocolloids. They are also used for production of defined phycocolloid oligomers for pharmacy and immunology (Dyrset, N., K.Q. Lystad, and D.W. Levine. 1997. Development of a fermentation process for production of a K-carrageenase from Pseudomonas carrageenovora. Enzyme and Microbial Technology. 20(6): 418-423). • Carrageenases provide the opportunity to investigate the structure-function relationships of the hydrolases that degrade self-associating sulfated polysaccharides (Michel, G., L. Chantlat, E. Fanchon, B. Henrissat, B. Kloareg, and O. Didweberg. 2001. The i- carrageenase of Alteromonas fortis. Journal of Biological Chemistry. 276(43): 40202-40209). According to the present invention, it is provided with an indigenous, novel halotolerant marine bacterium, identified as Pseudomonas spp, having a potency of degrading K-carrageenan into lower molecular weight substances. The present invention also relates to a novel medium composition used for maximizing production of K-carrageenase having following physicochemical properties (1) Optimum substrate concentration: 0.02%; (2) Optimum temperature: 40°C; (3) Heat stability: between 20-50°C; (4) Optimum pH: 5.6 and 7.7; (5) Substrate specificity: highly specific to K-carrageenan, does not hydrolyze λ and i carrageenan and LMP agarose; (6) Storage stability: for a period of 15days when stored at -20°C; sensitive to freezing & thawing (7) Solubility: soluble in water; (8) Molecular weight: The molecular weight was determined by SDS polyacrylamide gel electrophoresis (SDS PAGE), with the resuh that the molecular weight is 128KDa. No report is available on K-carrageenase having such a high molecular weight. According to the present invention, still furthermore, it is provided a method for preparing protoplast of Kappaphycus alvarezii using K- carrageenase. In the present invention, for the first time, a novel halotolerant marine bacterium, Pseudomonas spp., was isolated, from West coast of India, having the potency of producing K- carrageenase. In order to maximize K-carrageenase production, a novel medium composition was defined having minimum components and their optimum concentration using statistical optimization method. By following statistical optimization it was feasible to increase the specific activity of crude K- carrageenase by 32 fold. The inventive steps adopted in the present invention are (i) the process alleviate the need of multi-steps for the purification of enzymes ; (ii) the wide pH range from 4 to 10 in the present invention is feasible to achieve high specific activity of K- carrageenase; (iii) the culture medium dispenses the need of multiple components; (iv) the process utilizes minimum concentration of substrate in the culture medium essential for enzyme induction; (v) the process dispenses the need of low temperature (20°C) for maximum recovery of K- carrageenase ; (vi) maximum K- carrageenase can be recovered at a wide range of temperature between 25°C to 50°C ; (vii) the components in the culture medium dispenses the need of co-cultivating carrageenan producers with that of carrageenase non-producers to control K- carrageenase production. The following examples are given by way of illustration of the present invention and should not be construed to limit the scope of present invention. EXAMPLE 1 The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g.l00ml-1) carrageenan - 0.003, yeast extract -0.01, sodium chloride- 0.3, dipotassium hydrogen phosphate- 0.04 and potassium dihydrogen phosphate- 0.003 at pH 6.3. This was incubated at 30°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 50% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were re suspended in 10 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 9.2 galactose units/ mg protein. EXAMPLE 2 The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. lOOml"') carrageenan - 0.03, yeast extract - 0.01, sodium chloride - 0.3, dipotassium hydrogen phosphate - 0.004 and potassium dihydrogen phosphate - 0.03 at pH 8.4. This was incubated at 30°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifiaging the suspension at 8000rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 40%ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 15 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 8.4 galactose units/ mg protein EXAMPLE 3 The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. lOOml"') carrageenan - 0.03, yeast extract - 0.1, sodium chloride - 0.3, dipotassium hydrogen phosphate - 0.004 and potassium dihydrogen phosphate - 0.003 at pH 5.1. This was incubated at 35°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 55% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 20 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 24.2 galactose units/ mg protein. EXAMPLE 4 The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. l00ml-1) carrageenan - 0.03, yeast extract -0.1, sodium chloride - 3.0, dipotassium hydrogen phosphate - 0.004 and potassium dihydrogen phosphate - 0.003 at pH 8.0. This was incubated at 40°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 70% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 25 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 10.5 galactose units/ mg protein. EXAMPLE 5 The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. l00ml-1) carrageenan - 0.003, yeast extract -0.1, sodium chloride - 3.0, dipotassium hydrogen phosphate - 0.04 and potassium dihydrogen phosphate - 0.003 at pH 8.4. This was incubated at 25°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 30% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 15 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 16.2 galactose units/ mg protein. EXAMPLE 6 The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. l00ml') carrageenan - 0.03, yeast extract -0.01, sodium chloride - 3.0, dipotassium hydrogen phosphate - 0.04 and potassium dihydrogen phosphate - 0.03 at pH 7.1. This was incubated at 25'C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 40% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 15 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 14.8 galactose units/ mg protein. EXAMPLE 7 The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. l00ml-1) carrageenan - 0.03, yeast extract -0.1, sodium chloride - 0.3, dipotassium hydrogen phosphate - 0.04 and potassium dihydrogen phosphate - 0.03 at pH 9.0. This was incubated at 40°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 75% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 30 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 8.9 galactose units/ mg protein. EXAMPLE 8 The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. l00ml-1) carrageenan - 0.003, yeast extract -0.1, sodium chloride - 3.0, dipotassium hydrogen phosphate - 0.004 and potassium dihydrogen phosphate - 0.03 at pH 7.1. This was incubated at 30°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 65% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 25 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 11.4 galactose units/ mg protein. EXAMPLE 9 The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. lOOml"') carrageenan - 0.03, yeast extract -0.01, sodium chloride - 3.0, dipotassium hydrogen phosphate - 0.04 and potassium dihydrogen phosphate - 0.003 at pH 6.3. This was incubated at 30°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 55% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4'C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 15 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 11.8 galactose units/ mg protein. EXAMPLE 10 The isolated Pseudomonas spp. was inoculated in a 250 ml conical flask containing 100 ml of liquid medium comprising of (g. l00ml-1) carrageenan - 0.003, yeast extract -0.1, sodium chloride - 0.3, dipotassium hydrogen phosphate - 0.04 and potassium dihydrogen phosphate - 0.03 at pH 5.1. This was incubated at 35°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 35% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 25 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 17.3 galactose units/ mg protein. EXAMPLE 11 The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing l00ml of liquid medium comprising of (g. l00ml') carrageenan - 0.003, yeast extract -0.01, sodium chloride - 3.0, dipotassium hydrogen phosphate - 0.004 and potassium dihydrogen phosphate - 0.03 at pH 4.5. This was incubated at 40°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 70% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 30 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 5.9 galactose units/ mg protein. EXAMPLE 12 The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. l00ml-1) carrageenan - 0.003, yeast extract -0.01, sodium chloride - 0.3, dipotassium hydrogen phosphate - 0.004 and potassium dihydrogen phosphate - 0.003 at pH 5.1. This was incubated at 35°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifiaging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 40% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 15 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 17.4 galactose units/ mg protein. EXAMPLE 13 The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. l00ml"') carrageenan - 0.3, yeast extract -0.04, sodium chloride - 3.0, dipotassium hydrogen phosphate - 0.03 and potassium dihydrogen phosphate - 0.01 at pH 5.6. This was incubated at 35°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 60% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 20 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded an enzyme fraction having specific activity of 188.8 galactose units/ mg protein. Advantages; The main advantages of the present invention are: 1. In order to maximize kappa carrageenase production in a simple manner, a novel medium composition for growth of novel bacterium is defined having minimal components and their optimum concentration using statistical optimization method to reduce number of experiments, save time and chemicals and to improve higher authenticity of the results by observing combined effect to all the factors influencing enzyme production. 2. The present invention provides K- carrageenase with high specific activity upto 200 galactose units / mg protein. 3. The present K- carrageenase have the molecular weight 128KDa. 4. The present K- carrageenase have excellent K- carrageenan hydrolyzing activity. 5. The present K- carrageenase have activity in alkaline and acidic conditions. 6. The present K- carrageenase have higher temperature stability. 7. The present K- carrageenase have high substrate specificity. 8. The present K- carrageenase have prolonged storage stability. 9. The present K- carrageenase have capability to generate protoplast of Kappaphycus alvarezii We Claim: 1. A method for the preparation of K-carrageenase, wherein said method comprising the steps of: (i) isolating the bacterial culture from decayed carrageenophyte by growing it in a culture medium containing carrageenan as the only carbon source; (ii) cultivating the bacterium in an statistically optimized liquid medium containing components in the concentration range of (g 100ml-1) a) carrageenan 0.001-3.0; b) yeast extract 0.01-1.0; c) sodium chloride 0.5-15.0; d) K2HPO4 0.01-0.5; e) KH2PO4 0.005-0.05, on a rotary shaker for a period in the range of 16-72 hours and temperature in the range of 15-50°C; (iii) centrifuging the culture suspension in the range of 5000-8000 rpm for a period in the range of 20-40 min and obtaining cell free extract as supernatant and discarding the settled pellets; (iv) purifying the crude enzyme (supernatant) containing unwanted impurities other than K- carrageenase by treating with ammonium sulphate in the concentration range of 20-80% (wt/vol) at a temperature in the range of 3-15°C and aging the mixture for a period in the range of 12-36 hours; (v) centrifuging the mixture obtained in step (iv) in the range of 5000-8000rpm and at a temperature in the range of 3-15°C to obtain pellets of precipitated protein and discarding the supernatant; (vi) re-suspending the pellets obtained in step (v) in Tris- HC1 buffer solution of concentration in the range of 10-30 Mm; (vii) dialyzing the suspension obtained in step (vii) for removing the adhered ammonium sulphate against the same buffer; (viii) further purifying the partially purified enzyme using gel filtration technique to obtain desired purified K-carrageenase. 2. A method as claimed in claim 1, wherein, the said bacterium, Pseudomonas sp.have the following characteristics: a) halophilic; b) gram negative, exhibits gram variability; c) motile aerobic rods; d) it degrades algal polysaccharide i.e. K- carrageenan. 3. A method as claimed in claim 1, wherein the specific activity of said K- carrageenase is in the range of 10- 200 galactose units / mg protein. 4. A method as claimed in claim 1, wherein the said K- carrageenase have the molecular weight 128KDa.

Full Text

A METHOD FOR THE PREPARATION OF K-CARRAGEENASE
Field of invention:
The present invention relates to a method for the preparation of K-carrageenase. More particularly, the present invention relates to a method for the preparation of K-carrageenase by using halotolerant marine gram negative bacteria Pseudomonas sp. with accession number MTCC 5261.
Background and prior art of the invention:
The potential uses of K- carrageenase is to obtain low molecular weight carbohydrates, for kelp digestion, for prevention of biofouling by controlling red algal bloom formation, to obtain fine chemicals and for algal biotechnology.
Carrageenan is a natural ingredient obtained from certain species of the red seaweed; class Rhodophyceae (Greer, C.W., and W. Yaphe.1984. Enaymatic analysis of carrageenans: Structure of carrageenan from Eucheuma nudum. Hydrobiologia. 116/117: 563-567). Carrageenan is a linear polysaccharide made up of repeating dissacharide sequence of 1,3 linked P-D-galactopyranose called the A residue and a-D-galactopyranose residues linked through positions 1,4 called the B residue. Carrageenans are distinguished from agars in that the B units in carrageenan are in the D form whereas they are in the L form in agar. The regular backbone of the basic structure of carrageenan is disrupted by a more or less ordered distribution of sulfate hemi ester groups. Carrageenan can also contain some methoxy and pyruvate groups. Popular sources for carrageenan are Chondrus, Eucheuma (Kappaphycus), Gigartina and Iridaea species. Three basic types of carrageenan are available. Kappa (K), iota (i) and lambda (A,) carrageenan which are obtained from Chondrus, Eucheuma and Gigartina species, which differ in the number and location of sulfate ester substitution, K and i-carrageenan form thermally reversible gels in the presence of K+, Ca+2 or NH4+ but do not gel in the Na+
form.
Hydrolases, which degrade carrageenans at P-1,4 linkages, are known as carrageenases. Three types of enzymes, viz. K, I and λ,-carrageenases, have been isolated from various marine bacteria. They all are endohydrolases that cleave the P-1,4 linkages of
carrageenans yielding products of the neocarrabiose series (Michel, G., L. Chantlat, E. Fanchon, B. Henrissat, B. Kloareg, and O. Didweberg. 2001. The i- carrageenase of Alteromonas fords. Journal of Biological Chemistry. 276(43): 40202-40209). K-carrageenase has large-scale application and industrial demand in the forth-coming years (Ostgaard, K., B.F. Wangen, S.H. Knutsen, and I.M. Aasen. 1993. Large scale production and purification of K-carrageenase from Pseudomonas carrageenovora for applications in seaweed biotechnology. Enzyme and Microbial Technology. 15(4): 326-333).
Jhonston and McCandless in a paper entitled "Enzymic hydrolysis of the potassium chloride soluble fraction of carrageenan: properties of λ,-carrageenases from -Pseudomonas carrageenovora" in Canadian Journal of Microbiology 19: (1973) p.p.779-788, has reported that carrageenase from Pseudomonas carrageenovora exhibited activity only against KCl soluble fraction of carrageenan i.e. λ,-carrageenan. They could improve the yield of λ- carrageenase but could not totally eliminate simultaneous production of K-carrageenase. Also, after using multiple and complicated steps of purification, specific activity achieved was only 7 galactose units/mg protein which had temperature and pH optima 28°C and 6.2 respectively. The drawback of this work is that carrageenase is active only in acidic condition and at 28°C temperature. Hence it can not be used in alkaline condition as well as at elevated temperature. Moreover, the process did not yield noteworthy purification of enzyme, inspite of using complicated enzyme purification steps.
Bellion et al. in a paper entitled "The degradation of Eucheuma spinosum and Eucheuma cottoni carrageenans by i and K-carrageenases from marine bacteria" in Canadian Journal of Microbiology 28(7): (1982) p.p. 874-880 has reported the degradation oi Eucheuma spinosum and Eucheuma cottonii carrageenans by i-carrageenase and K-carrageenase from marine Pseudomonas carrageenovora and identified the hydrolyzed products. The bacterium was cultivated in a medium consisting of g. l-1 NaCl 25; K2HPO4 0.1; MgSO4 7H2O 5.0; CaCl2H2O 0.2; casamino acids 2.5; carrageenan 2.5; 0.3 % FeSO4 (l0ml/lit) and optimum incubation temperature of 22°C. The drawback is that the medium used for the production of carrageenase by this bacterium consisted of 7 components. Moreover, optimum incubation temperature used was 22°C, which is not feasible for the cultivation
of this type of bacteria in temperate countries without cooling device especially in summer.
Sarwar et al. in a paper entitled "Potentiality of artificial sea water salts for the production of carrageenase by a marine Cytophaga species" in Microbiology and Immunology. 29(5): (1985) p.p.405-411 and "Purification of a K-carrageenase from marine Cytophaga species" in Microbiology and Immunology. 31(9): (1987) p.p. 869-877 wherein, 8 components were used in the medium for the production of carrageenase by a marine Cytophaga sp. Moreover, this culture required a suitable combination of NaCl and MgCl2 for carrageenase production. The pH and temperature optima were 7.6 and 25°C respectively. The activity achieved after following complicated steps of purification was only 5.0 galactose units/ mg protein. The drawback of this work is that the presence of NaCl and MgCl2 in the medium is a must for carrageenase production and inspite of using eight medium components and complicated steps of purification; only 5.0 galactose units/ mg protein was obtained as enzyme activity. This low yield makes the enzyme production commercially uneconomical.
Fleurence et al. in a paper entitled "Use of enzymatic cell wall degradation for improvement of protein extraction from Chondrus crispus, Gracilaria verrucosa and Falmaria palmata" in Journal of Applied Phycology 7: (1995) 393-397) wherein, K-carrageenase was reported to have maximum activity between pH 6.5-6.8 and at 45°C and lower activity at acidic and alkaline conditions. The drawback of this work is that the enzyme is active only at neutral pH hence can not be used either in acidic and alkaline conditions. Moreover, poor activity at lower temperature makes its applicability limited to higher temperature .
Dyrset et al. in a paper entitled "Development of a fermentation process for production of a K-carrageenase from Pseudomonas carrageenovora" in Enzyme and Microbial Technology 20(6): (1997) p.p. 418-423 has reported a fermentation process for the production of K-carrageenase using two strains of Pseudomonas carrageenovora. The medium used for this study contained gl'of CaCl2, 2H2O 0.2; Casamino acid 6.8; KCl 0.3; K2HPO43.0; MgSO4, 7H2O 0.5; NaCl 20.0; NH4CI 0.7; (NH4)2 SO4 5.0; Carrageenan 2.5. The pH of the medium was 7.0 and temperature was 20°C. The drawback of this work is that large number of components as well as high substrate concentration is
required in the medium and the maintenance of pH 7.0 with all these components is difficult. Besides, the fermentation process is carried out at 20°C, which requires special device for maintaining such low temperature
Araki et al. in a paper entitled "Purification and characterization of K-carrageenase form a marine bacterium Vibrio sp. CA-, 1004" in Fisheries Science 65 (6): (1999) p.p. 937-942 wherein, they purified and characterized K-carrageenase, an inducible enzyme, from a marine bacterium Vibrio species, the molecular weight of which was 35 KDa and maximum enzyme activity at pH 8.0 and temperature 40°C. The medium used for this study contained g r'of peptone 5.0; yeast extract 1.0; NaCl 30; MgSO4 0.5; K2HPO4 2.0; KH2PO4 0.4; carrageenan 15. The activity of crude carrageenase obtained was 0.949 galactose units/ mg protein. The drawback of this work is that production medium containing seven components yielded carrageenase with activity of only 0.949 galactose units/mg protein. Such low activity would invariably make the process uneconomical and unfeasible.
Japanese patent No. JP2001136961 (2001) assigned to Okita Yuji et al. has disclosed a "Method for controlling carrageenase producing ability of bacterium" is described. Here, a method has been described to control the carrageenase producing ability of a carrageenase producing bacterium, by culturing it in the presence of a bacterium free from the carrageenase producing ability or its culture product. The drawback of this invention is that production of carrageenase was controlled only by co-cultivating carrageenase producer with that of carrageenase non producer.
Japanese patent No. JP 2000116376 (2000) assigned to Araki Toshiyoshi entitled "New K- carrageenase, microorganism for producing the same, production of carrageenase and its use" has disclosed that K- carrageenase has decomposition activity against K-carrageenan. This enzyme decomposed K-carrageenan into neocarrabiose and neocarratetraose and had pH optima of 8.0. The drawback of this invention is that the enzyme had only alkaline pH optima hence can not be used in acidic condition. Japanese patent No. JP 1006656 (1998) assigned to Christian G et al. entitled "Production of K- carrageenase" has disclosed the productivity of K-carrageenase by Pseudomonas carrageenovora, Alteromonas or Cytophoga which was substantially improved by controlling the pH of a culture medium by nitrogen containing base (ammonium water) to
be assimilated by these bacteria. By this, K-carrageenase production could be improved from >= 20 galactose Units/ml to 40 to 60 galactose Units/ml. The drawback of this invention is that they could achieve only 3 fold purification after controlling pH which is not viable commercially.
Canadian Patent No. CN1544623 (2004) assigned to Haigin M et al. entitled "Carrageenin catabolic enzymes it's preparing process and application", wherein, an enzyme that can degrade K-carrageenan to prepare oligocarrageenan and degrade beta-1,4 indican bond of K-carrageenan having a molecular weight of 30KDa was obtained. Cytophaga sp. was cultured at 28-35 deg. C, centrifuged to obtain crude enzyme and concentrated it by using 40-80% ammonium sulphate. This method was compared with chemical method; it had simple preparing course, high product yield, and stable quality and ensure the activity research and development of oligosaccharide etc. The drawback of the present invention is that only salting out method was used for concentrating enzyme which does not give substantially concentrated /purified enzyme preparation.
Objects of the invention:
The main object of the present invention is to provide a method for the preparation of K-
carrageenase.
Another object of the present invention is to provide a method for the preparation of K-
carrageenase by using halotolerant marine gram negative bacteria.
Further another object of the present invention is to provide an improved K- carrageenase
by using halotolerant marine gram negative bacteria which grows in a novel medium
composition with optimum concentration.
Yet another object of the present invention is to maximize carrageenase production in a
simple manner involving less complicated techniques.
Yet another object of the present invention is to provide K- carrageenase having excellent
K- carrageenan hydrolyzing activity.
Yet another object of the present investigation is to obtain K- carrageenase having
activity in alkaline and acidic conditions.
Yet another object of the present investigation is to obtain K- carrageenase having
higher temperature stability.
Yet another object of the present investigation is to obtain K- carrageenase having high
substrate specificity.
Yet another object of the present investigation is to obtain K- carrageenase having
prolonged storage stability.
Yet another object of the present investigation is to obtain K- carrageenase having high
substrate specificity.
Yet another object of the present investigation is to obtain K- carrageenase having
prolonged storage stability.
Yet another object of the present investigation is to obtain K- carrageenase having
capability to generate protoplast of Kappaphycus alvarezii.
Summary of the invention:
The present invention deals with a novel halotolerant marine bacterium, Pseudomonas spp. with accession no MTCC 5261 useful for the production of high activity K-carrageenase. In order to maximize K-carrageenase production in a simple manner, a new medium composition is defined having minimum components and their optimum concentration using statistical optimization method to reduce number of experiments, save time and chemicals and to improve higher authenticity of the results by observing combined effect of all the factors influencing enzyme production.
Detailed description of the invention:
Accordingly, the present invention provides a method for the preparation of K-
carrageenase, wherein the said method comprising the steps of:
(i) isolating the bacterial culture from decayed carrageenophyte by growing it in a culture medium containing carrageenan as the only carbon source; (ii) cultivating the bacterium in an statistically optimized liquid medium containing components in the concentration range of (g 100ml-1) a) carrageenan 0.001-3.0; b) yeast extract 0.01-1.0; c) sodium chloride 0.5-15.0; d) K2HPO4 0.01-0.5; e) KH2PO4 0.005-0.05, on a rotary shaker for a period in the range of 16-72 hours and temperature in the range of 15-50°C;
(iii) centrifuging the culture suspension in the range of 5000-8000 rpm for a period in the range of 20-40 min and obtaining cell free extract as supernatant and discarding the settled pellets;

(iv) purifying the crude enzyme (supernatant) containing unwanted impurities other than
K- carrageenase by treating with ammonium sulphate in the concentration range of 20-
80% (wt/vol) at a temperature in the range of 3-15°C and aging the mixture for a period
in the range of 12-36 hours;
(v) centrifuging the mixture obtained in step (iv) in the range of 5000-8000rpm and at a
temperature in the range of 3-15°C to obtain pellets of precipitated protein and
discarding the supernatant;
(vi) re-suspending the pellets obtained in step (v) in Tris- HC1 buffer solution of
concentration in the range of 10-30 Mm;
(vii) dialyzing the suspension obtained in step (vii) for removing the adhered ammonium
sulphate against the same buffer;
(viii) further purifying the partially purified enzyme using gel filtration technique to
obtain desired purified K-carrageenase.
In an embodiment of the present invention, the said bacterium, Pseudomonas sp have the following characteristics:
a) halophilic;
b) gram negative, exhibits gram variability;
c) motile aerobic rods;
d) it degrades algal polysaccharide i.e. K- carrageenan.
In another embodiment of the present invention, the said K- carrageenase is purified
using gel filtration technique on Sepharose CL-4B.
Further, in another embodiment of the present invention, the specific activity of said K-
carrageenase is in the range of 10- 200 galactose units / mg protein.
Yet in another embodiment of the present invention, the said K- carrageenase have the
molecular weight 128KDa.
Still in another embodiment of the present invention, the said K- carrageenase have
excellent K- carrageenanse hydrolyzing activity.
Still in another embodiment of the present invention, the said K- carrageenase have
activity in alkaline and acidic conditions.
Still in another embodiment of the present invention, the said K- carrageenase have
higher temperature stability.
Still in another embodiment of the present invention, the said K- carrageenase have high
substrate specificity.
substrate specificity.
Still in another embodiment of the present invention, the said K- carrageenase have
prolonged storage stability.
Still in another embodiment of the present invention, K- carrageenase having capability to
generate protoplast of Kappaphycus alvarezii
The present invention provides a process for improved K-carrageenase production and method for preparation thereof which comprises of the isolation of marine bacterial cultures from seawater and sediment located in the vicinity of red algae and decayed carrageenophyte. These bacteria were grown on a solid culture medium containing carrageenan as the only carbon source. Bacterial colonies producing pits or holes in the above said solid medium were further purified and the bacterium producing maximum depression was selected for further studies.
The purified bacterium was then inoculated in a liquid medium containing components in the concentration preferably in range of (g lOOml"') (i) carrageenan 0.005-6.0 (ii) yeast extract 0.0051-3.0 (iii) sodium chloride 0.1-20.0 (iv) K2HPO4 0.001-1.5 (v) KH2PO4 0.001-0.1 for its cultivation. The inoculated liquid culture medium was incubated on a rotary shaker for a period in the range of 12-90 hours and temperature in the range of 10-60°C for production of K-carrageenase. The cultivated culture suspension was then centrifuging preferably in the range of 4000-10000 rpm for a period in the range of 20-70 minutes to obtain crude extracellular K-carrageenase as supernatant (cell free extract). The extracellular crude enzyme (supernatant) was then partially purified by salting out method, using preferably ammonium sulfate in the concentration range of 10-100% (wt/ vol) and at a temperature in the range of 3-10°C and aging the mixture for a period in the range of 12-36 hours to eliminate majority of unwanted protein impurities. This suspension containing ammonium sulfate precipitated proteins was centrifuged preferably in the range of 4000-l0000rpm and at a temperature in the range of 3-10°C to obtain pellets containing mainly K- carrageenase and discarding the supernatant containing other protein impurities. The pellets obtained by centrifugation (containing mainly K-carrageenase) were re suspended in minimum volume of preferably 5-40 mM Tris HCl buffer solution. For the removal of excess ammonium sulfate and other low molecular weight impurities including proteins the partially purified K- carrageenase solution was
dialyzed against 0.02 mM Tris HCl buffer using dialysis bag having 12,000 molecular weight cutoffs.
For further purification of ammonium sulfate precipitated K- carrageenase, gel filtration technique on Sepharose CL-4B was used and K- carrageenase rich fractions were recovered by eluting them using Tris HCl buffer preferably in the concentration range of 5-50mM. The molecular weight of purified K- carrageenase fraction was determined by repeated gel filtration method, noting its elution volume (Ve), calculating its Ve/Vo (Vo is void volume of the column) and comparing it with a plot of log of molecular weight Vs Ve/Vo of standard molecular weight proteins markers. Potential uses of this enzyme are as follows:
• To improve the physical properties of polysaccharides, conversion to oligosaccharide may be the best choice. The enzymatic degradation of carrageenan yields novel products with high bioactivity.
• The enzymes produced by marine bacteria could effectively control red algal bloom contamination. Thus, it prevents bio fouling of submerged marine surface or pipes by acting on complex polysaccharide layers.
• These enzymes are essential tools to study structure and assembly of red algal cell walls (Gall, Y. L., J.P.Braud and B. Kloareg. 1990. Protoplast production in Chondrus crispus gametophytes (Gigartinales, Rhodophyta). Plant Cell Reports. 8: 582-585).
• These enzymes are useful for kelp digestion (Sarwar, G., H. Oda, T. Sakata, and D. Kakimoto. 1985. Potentiality of artificial sea water salts for the production of carrageenase by a marine Cytophaga species. Microbiology Immunology. 29(5): 405-411). The digested products in turn can be used as carbon source for the growth of bacteria. They are also used for the extraction of fine chemicals from these algae.
• Most red seaweed possesses high level of proteins (10-30% dry weight) (Morgan, C, J.L.C. Wright and J. Simpson. 1980. Review of chemical constituents of the red alga Palmaria palmate (dulse). Economic Botany. 34: 27-50; Mabeau, S., and J. Fleurence. 1993. Seaweed in food products: biochemical and nutritional aspects. Trends Foods Science & Technology. 4: 103-107). These proteins can be extracted by hydrolytic enzymes like carrageenase (Fleurence, J., L. Massiani, O. Guyader, and S.
Mabeau.1995. Use of enzymatic cell wall degradation for improvement of protein extraction from Chondrus crispus, Gracilaria verrucosa and Palmaria palmate. Journal of Applied Phycology. 7: 393-397). For example, the degradation of cell wall polysaccharides by hydrolytic enzymes is used for the isolation of extensin, a protein linked to cell wall polysaccharide of higher plants (Lamport, D.T.A.1969. The isolation and partial characterization of hydrodyproline rich glycolipides obtained by enzymic degradation on primary cell walls. Biochemistry. 3: 1155-1163).
• They can be used for the isolation of protoplast, which can be used for genetic engineering experiments for the production of improved algal strains (Chen, L.C.M., J.S. Craigie, and Z.K. Xie. 1994. Protoplast production from Porphyra linearis using a simplified agarase procedure capable of commercial application. Journal of Applied Phycology. 6: 35-39).
• They are used in molecular biology to prevent severe separation problems occurring in the presence of phycocolloids. They are also used for production of defined phycocolloid oligomers for pharmacy and immunology (Dyrset, N., K.Q. Lystad, and D.W. Levine. 1997. Development of a fermentation process for production of a K-carrageenase from Pseudomonas carrageenovora. Enzyme and Microbial Technology. 20(6): 418-423).
• Carrageenases provide the opportunity to investigate the structure-function relationships of the hydrolases that degrade self-associating sulfated polysaccharides (Michel, G., L. Chantlat, E. Fanchon, B. Henrissat, B. Kloareg, and O. Didweberg. 2001. The i- carrageenase of Alteromonas fortis. Journal of Biological Chemistry. 276(43): 40202-40209).
According to the present invention, it is provided with an indigenous, novel halotolerant marine bacterium, identified as Pseudomonas spp, having a potency of degrading K-carrageenan into lower molecular weight substances. The present invention also relates to a novel medium composition used for maximizing production of K-carrageenase having following physicochemical properties
(1) Optimum substrate concentration: 0.02%; (2) Optimum temperature: 40°C; (3) Heat stability: between 20-50°C; (4) Optimum pH: 5.6 and 7.7; (5) Substrate specificity: highly specific to K-carrageenan, does not hydrolyze λ and i carrageenan and LMP
agarose; (6) Storage stability: for a period of 15days when stored at -20°C; sensitive to freezing & thawing (7) Solubility: soluble in water; (8) Molecular weight: The molecular weight was determined by SDS polyacrylamide gel electrophoresis (SDS PAGE), with the resuh that the molecular weight is 128KDa. No report is available on K-carrageenase having such a high molecular weight.
According to the present invention, still furthermore, it is provided a method for preparing protoplast of Kappaphycus alvarezii using K- carrageenase. In the present invention, for the first time, a novel halotolerant marine bacterium, Pseudomonas spp., was isolated, from West coast of India, having the potency of producing K- carrageenase. In order to maximize K-carrageenase production, a novel medium composition was defined having minimum components and their optimum concentration using statistical optimization method. By following statistical optimization it was feasible to increase the specific activity of crude K- carrageenase by 32 fold. The inventive steps adopted in the present invention are (i) the process alleviate the need of multi-steps for the purification of enzymes ; (ii) the wide pH range from 4 to 10 in the present invention is feasible to achieve high specific activity of K- carrageenase; (iii) the culture medium dispenses the need of multiple components; (iv) the process utilizes minimum concentration of substrate in the culture medium essential for enzyme induction; (v) the process dispenses the need of low temperature (20°C) for maximum recovery of K- carrageenase ; (vi) maximum K- carrageenase can be recovered at a wide range of temperature between 25°C to 50°C ; (vii) the components in the culture medium dispenses the need of co-cultivating carrageenan producers with that of carrageenase non-producers to control K- carrageenase production.
The following examples are given by way of illustration of the present invention and should not be construed to limit the scope of present invention.
EXAMPLE 1
The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g.l00ml-1) carrageenan - 0.003, yeast extract -0.01, sodium chloride- 0.3, dipotassium hydrogen phosphate- 0.04 and potassium
dihydrogen phosphate- 0.003 at pH 6.3. This was incubated at 30°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 50% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were re suspended in 10 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 9.2 galactose units/ mg protein.
EXAMPLE 2
The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. lOOml"') carrageenan - 0.03, yeast extract - 0.01, sodium chloride - 0.3, dipotassium hydrogen phosphate - 0.004 and potassium dihydrogen phosphate - 0.03 at pH 8.4. This was incubated at 30°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifiaging the suspension at 8000rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 40%ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 15 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 8.4 galactose units/ mg protein
EXAMPLE 3
The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. lOOml"') carrageenan - 0.03, yeast extract - 0.1, sodium chloride - 0.3, dipotassium hydrogen phosphate - 0.004 and potassium dihydrogen phosphate - 0.003 at pH 5.1. This was incubated at 35°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell
free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 55% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 20 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 24.2 galactose units/ mg protein.
EXAMPLE 4
The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. l00ml-1) carrageenan - 0.03, yeast extract -0.1, sodium chloride - 3.0, dipotassium hydrogen phosphate - 0.004 and potassium dihydrogen phosphate - 0.003 at pH 8.0. This was incubated at 40°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 70% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 25 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 10.5 galactose units/ mg protein.
EXAMPLE 5
The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. l00ml-1) carrageenan - 0.003, yeast extract -0.1, sodium chloride - 3.0, dipotassium hydrogen phosphate - 0.04 and potassium dihydrogen phosphate - 0.003 at pH 8.4. This was incubated at 25°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 30% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution
was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 15 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 16.2 galactose units/ mg protein.
EXAMPLE 6
The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. l00ml') carrageenan - 0.03, yeast extract -0.01, sodium chloride - 3.0, dipotassium hydrogen phosphate - 0.04 and potassium dihydrogen phosphate - 0.03 at pH 7.1. This was incubated at 25'C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 40% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 15 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 14.8 galactose units/ mg protein.
EXAMPLE 7
The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. l00ml-1) carrageenan - 0.03, yeast extract -0.1, sodium chloride - 0.3, dipotassium hydrogen phosphate - 0.04 and potassium dihydrogen phosphate - 0.03 at pH 9.0. This was incubated at 40°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 75% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 30 mM Tris- HCl buffer and dialyzed against
the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 8.9 galactose units/ mg protein.
EXAMPLE 8
The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. l00ml-1) carrageenan - 0.003, yeast extract -0.1, sodium chloride - 3.0, dipotassium hydrogen phosphate - 0.004 and potassium dihydrogen phosphate - 0.03 at pH 7.1. This was incubated at 30°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 65% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 25 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 11.4 galactose units/ mg protein.
EXAMPLE 9
The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. lOOml"') carrageenan - 0.03, yeast extract -0.01, sodium chloride - 3.0, dipotassium hydrogen phosphate - 0.04 and potassium dihydrogen phosphate - 0.003 at pH 6.3. This was incubated at 30°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 55% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4'C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 15 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 11.8 galactose units/ mg protein.
EXAMPLE 10
The isolated Pseudomonas spp. was inoculated in a 250 ml conical flask containing 100 ml of liquid medium comprising of (g. l00ml-1) carrageenan - 0.003, yeast extract -0.1, sodium chloride - 0.3, dipotassium hydrogen phosphate - 0.04 and potassium dihydrogen phosphate - 0.03 at pH 5.1. This was incubated at 35°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 35% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 25 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 17.3 galactose units/ mg protein.
EXAMPLE 11
The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing l00ml of liquid medium comprising of (g. l00ml') carrageenan - 0.003, yeast extract -0.01, sodium chloride - 3.0, dipotassium hydrogen phosphate - 0.004 and potassium dihydrogen phosphate - 0.03 at pH 4.5. This was incubated at 40°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 70% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 30 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 5.9 galactose units/ mg protein.
EXAMPLE 12
The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. l00ml-1) carrageenan - 0.003, yeast extract -0.01,
sodium chloride - 0.3, dipotassium hydrogen phosphate - 0.004 and potassium dihydrogen phosphate - 0.003 at pH 5.1. This was incubated at 35°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifiaging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 40% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 15 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded a specific activity of 17.4 galactose units/ mg protein.
EXAMPLE 13
The isolated Pseudomonas spp. was inoculated in a 250ml conical flask containing 100ml of liquid medium comprising of (g. l00ml"') carrageenan - 0.3, yeast extract -0.04, sodium chloride - 3.0, dipotassium hydrogen phosphate - 0.03 and potassium dihydrogen phosphate - 0.01 at pH 5.6. This was incubated at 35°C on rotary shaker at 180 rpm (rev/min) for a period of 28 hours. The crude carrageenase was obtained as cell free extract after centrifuging the suspension at 8000 rpm for 15 minutes. This crude carrageenase was partially purified by treatment with 60% ammonium sulphate (wt/ vol) at a temperature of 4°C and aging the mixture for 24 hours. After incubation, the solution was centrifuged at 8000rpm at 4°C for 15 minutes to obtain pellets of precipitated protein. The obtained pellets were resuspended in 20 mM Tris- HCl buffer and dialyzed against the same buffer. The partially purified enzyme was further purified using gel filtration technique which yielded an enzyme fraction having specific activity of 188.8 galactose units/ mg protein.
Advantages;
The main advantages of the present invention are:
1. In order to maximize kappa carrageenase production in a simple manner, a novel medium composition for growth of novel bacterium is defined having minimal components and their optimum concentration using statistical optimization method to reduce number of experiments, save time and chemicals and to improve higher authenticity of the results by observing combined effect to all the factors influencing enzyme production.
2. The present invention provides K- carrageenase with high specific activity upto 200 galactose units / mg protein.
3. The present K- carrageenase have the molecular weight 128KDa.
4. The present K- carrageenase have excellent K- carrageenan hydrolyzing activity.
5. The present K- carrageenase have activity in alkaline and acidic conditions.
6. The present K- carrageenase have higher temperature stability.
7. The present K- carrageenase have high substrate specificity.
8. The present K- carrageenase have prolonged storage stability.
9. The present K- carrageenase have capability to generate protoplast of Kappaphycus alvarezii

We Claim:
1. A method for the preparation of K-carrageenase, wherein said method comprising the
steps of:
(i) isolating the bacterial culture from decayed carrageenophyte by growing it in a culture medium containing carrageenan as the only carbon source;
(ii) cultivating the bacterium in an statistically optimized liquid medium containing components in the concentration range of (g 100ml-1) a) carrageenan 0.001-3.0; b) yeast extract 0.01-1.0; c) sodium chloride 0.5-15.0; d) K2HPO4 0.01-0.5; e) KH2PO4 0.005-0.05, on a rotary shaker for a period in the range of 16-72 hours and temperature in the range of 15-50°C;
(iii) centrifuging the culture suspension in the range of 5000-8000 rpm for a period in the range of 20-40 min and obtaining cell free extract as supernatant and discarding the settled pellets;
(iv) purifying the crude enzyme (supernatant) containing unwanted impurities other than K- carrageenase by treating with ammonium sulphate in the concentration range of 20-80% (wt/vol) at a temperature in the range of 3-15°C and aging the mixture for a period in the range of 12-36 hours;
(v) centrifuging the mixture obtained in step (iv) in the range of 5000-8000rpm and at a temperature in the range of 3-15°C to obtain pellets of precipitated protein and discarding the supernatant;
(vi) re-suspending the pellets obtained in step (v) in Tris- HC1 buffer solution of concentration in the range of 10-30 Mm;
(vii) dialyzing the suspension obtained in step (vii) for removing the adhered ammonium sulphate against the same buffer;
(viii) further purifying the partially purified enzyme using gel filtration technique to obtain desired purified K-carrageenase.
2. A method as claimed in claim 1, wherein, the said bacterium, Pseudomonas sp.have
the following characteristics:
a) halophilic;
b) gram negative, exhibits gram variability;
c) motile aerobic rods;
d) it degrades algal polysaccharide i.e. K- carrageenan.
3. A method as claimed in claim 1, wherein the specific activity of said K- carrageenase is
in the range of 10- 200 galactose units / mg protein.
4. A method as claimed in claim 1, wherein the said K- carrageenase have the molecular weight 128KDa.

Documents:

858-DEL-2006-Abstract-(18-05-2012).pdf

858-del-2006-abstract.pdf

858-DEL-2006-Claims-(18-05-2012).pdf

858-del-2006-claims.pdf

858-DEL-2006-Correspondence Others-(18-05-2012).pdf

858-del-2006-Correspondence Others-(28-05-2012).pdf

858-del-2006-correspondence-others.pdf

858-DEL-2006-Description (Complete)-(18-05-2012).pdf

858-del-2006-description (complete).pdf

858-del-2006-form-1.pdf

858-del-2006-form-18.pdf

858-del-2006-form-2.pdf

858-DEL-2006-Form-3-(18-05-2012).pdf

858-del-2006-Form-3-(28-05-2012).pdf

858-del-2006-form-3.pdf

858-del-2006-form-5.pdf

858-del-2006-Petition-137-(28-05-2012).pdf

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Patent Number

253554

Indian Patent Application Number

858/DEL/2006

PG Journal Number

31/2012

Publication Date

03-Aug-2012

Grant Date

31-Jul-2012

Date of Filing

28-Mar-2006

Name of Patentee

COUNCIL OF SCIENTIFIC INDUSTRIAL RESEARCH

Applicant Address

ANUSANDHAN BHAWAN, 2, RAFI MARG, NEW DELHI - 110 001, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	YASMIN NAJMUDDIN KHAMBHATY	CENTRAL SALT & MARINE CHEMICALS RESEARCH INSTITUTE, GIJUBHAI BADHEKA MARG, BHAVNAGAR 364 002 GUJARAT, INDIA.
2	KALPANA HARESH MODY	CENTRAL SALT & MARINE CHEMICALS RESEARCH INSTITUTE, GIJUBHAI BADHEKA MARG, BHAVNAGAR 364 002 GUJARAT, INDIA.
3	BHAVANATH JHA	CENTRAL SALT & MARINE CHEMICALS RESEARCH INSTITUTE, GIJUBHAI BADHEKA MARG, BHAVNAGAR 364 002 GUJARAT, INDIA.

PCT International Classification Number

C12N 9/24

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA