关键词: 壳聚糖酶, Mitsuaria sp.K1, 发酵条件, 响应面法, 优化

Abstract: Nowadays，people pay much attention to chitosan and its degradation product due to its excellent physical characteristic and biological activity. In this study，a high Chitosanase-producing bacterium Mitsuaria sp.K1 was isolated from the soil of Qingdao seacoast by primary screening of plate specula and shaking cultivation. The optimization of fermentation conditions was studied by Response Surface Methodology. The results showed that，under the optimal composition of medium (1.0%powder chitosan，0.5%KNO3，0.22%KH2PO4，0.1%Na2HPO4，0.15%KCl，0.05%MgSO4?7H2O) and the optimal cultural condition(25.2 ℃ incubating temperature，25.4 hours incubating time，initial pH6.5，3% inoculation amount，100 mL medium/500 mL flask，160 r/min)，the maximal chitosanase activity of Mitsuaria sp.K1 could reach 11.56 U/mL which was 5.32 times of primary strain. In addition，due to Mitsuaria sp.K1 with lower temperature and shorter fermentation time of chitosanase production，it has a good potential in industrial fermentation.

Key words: chitosanase, Mitsuaria sp.K1, fermentation condition, response surface methodology, optimization