Effect of different carbon sources on endochitinase production by Colletotrichum gloeosporioides.
ABSTRACT The present work analyzes the production of endochitinase by Colletotrichum gloeosporioides, a phytopathogenic fungus, using six different carbon sources and two pH values. For quantitative assay of endochitinase activity in solution, the synthetic substrate 4-methylumbelliferyl-beta-D-N,N',N"-triacetylchitotrioside was used. The major productions were obtained at pH 7.0 and 9.0, when colloidal chitin and glucose were used, whereas xylose and lactose were not good carbon sources. When testing different concentrations of colloidal chitin, glucose and glucosamine, colloidal chitin 0.5% was the best substrate, giving values of 2.4 U at the fifth day. When using glucose, best production occurred at 0.3% concentration, after 5 days growth, with values of 1.31 U. Endochitinase production was markedly decreased in high levels of glucose and in all glucosamine concentrations tested. SDS-PAGE co-polymerized with glycol-chitin analysis showed three major activity bands of 200, 100, and 95 kDa, when incubated at 50 degrees C.
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ABSTRACT: Chitinase producing strain B-CM18 was isolated from chickpea rhizosphere and identified as Lysinibacillus fusiformis B-CM18. It showed in vitro antifungal activity against a wide range of fungal plant pathogens and was found to produce several PGPR activities. Further, a multivariate response surface methodology was used to evaluate the effects of different factors on chitinolytic activity and optimizing enzyme production. A central composite design was employed to achieve the highest chitinase production at optimum values of the process variables, viz., temperature (20-45 °C), sodium chloride (2-7%), starch (0.1-1%) and yeast extract (0.1-1%), added in the minimal medium supplemented with colloidal chitin (1-10%; w:w). The fit of the model (R(2) = 0.5692) was found to be significant. The production medium to achieve the highest chitinase production (101 U ml(-1) ) was composed of the minimal medium composed of chitin (6.09%), NaCl (4.5%), starch (0.55%) and yeast extract (0.55%) with temperature (32.5 °C). The results show that the optimization strategy led to an increase in chitinase production by 56.1-fold. The molecular mass of the chitinase was estimated to be 20 kDa by anion exchange and gel filtration chromatography. Further, purified chitinase showed strong antifungal activity against test pathogens. Overall, these results may serve as a base line data for enhancing the chitinolytic potential of bacterial antagonists for bio-management of chickpea pathogens. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).Journal of Basic Microbiology 05/2013; 53(5). DOI:10.1002/jobm.201100590 · 1.20 Impact Factor
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ABSTRACT: The current increase in the amount of shell waste produced by the shrimp industries has led to the need to find new methods for its disposal. In this study, statistical methodologies were used for chitinase and protease co-production optimization by Bacillus cereus SV1 in media containing shrimp shell powder. Medium composition and culture conditions were optimized using two statistical methods: Plackett–Burman design was applied to find the key ingredients and conditions for the best yield of enzymes production, and central composite design was used to optimize the levels of the five significant variables: shrimp shell powder (SSP), NH4Cl, CaCl2, K2HPO4 and speed of agitation. The medium optimization resulted in protease and chitinase activities of 8,445.8 U ml−1 and 82.8 mU ml−1, respectively. The crude chitinase exhibited maximal activity at 55°C and pH 7.0 using colloidal chitin as substrate. The metal ions Fe2+ and Mg2+ increased chitinase activity, while Hg2+ strongly inhibited this activity. The nucleotide sequencing of SV1 chitinase revealed an open reading frame containing 2,025 bp and encoding 642 amino acids.Annals of Microbiology 09/2011; 62(3). DOI:10.1007/s13213-011-0371-x · 1.04 Impact Factor
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ABSTRACT: A total of 39 chitinolytic bacteria were isolated from 77 rhizosphere soil samples collected from different crop fields in Tamil Nadu state, India. Among them, a strain designated as MML2270, which produced highest chitinolytic activity in primary and secondary screening in colloidal chitin agar was selected and later identified as Bacillus laterosporous. The production of chitinase by B. laterosporous was optimized using different growth media, substrate concentrations, pH, temperature and incubation period. The maximum chitinase production was observed in yeast nitrogen based medium (YNB) amended with 0.3% colloidal chitin at pH 8.0 and 35°C after four days of inoculation. Under this optimized growth condition, B. laterosporous MML2270 produced a total chitinase activity of 59.05 units/ml as against only 19.7 units/ml in the initial YNB medium stage, which is a three-fold increase.AFRICAN JOURNAL OF BIOTECHNOLOGY 01/2008; 7(15):2562-2568. · 0.57 Impact Factor