Screening And Culture Of Chitosanase-producing Marine Microorganisms

Chitosanase which catalyze the hydrolysis of glycosidic bonds of chitosan, couldhydrolyze chitosan into functional chitooligosaccharides. This research was to find newsourse of chitosanase with high enzyme activity from marine microorganisms, and providetechnical support and theoretic basis on enzymic preparation of chitooligosaccharides.The samples were from sea water, marine shells, mud, algae. The strain for further studywas screened from marine mud through methods of see-through circle and measuring enzymeactivity. The activity of chitosanase was up to0.235U/ml.The strain was inoculated on czapek’s medium, malt extract medium, PDA and chitosanmedium as shape of three points and splay character. The microscopic morph in cell cultureinserts and plate were observed. According to the morph character on different medium, thestrain was identificated as Aspergillus flavus.In this study, univariate tests were optimized, including different sources of carbon andnitrogen, the best concentration of carbon and nitrogen, additive amount of marine water,initial pH of medium, liquid volume, inoculation amount, culture temperature and time. Basedon the results, the best components of medium through RSM analysis: Glc3.0%, chitosan1.939%, peptone0.171%, sea water40%, initial pH7.44. The results of orthogonal test onculture condition: temperature22℃, time4days, inoculation2%, liquid volume20%.Under the best components of medium and culture condition, the activity of chitosanasewas up to0.379U/ml, which was61.28%higher than unoptimized.