【摘要】 采用二步发酵法,研究黏质沙雷氏菌的产几丁质酶发酵条件.在二步发酵产酶的过程中,通过单因素法优化得到二步发酵培养基中最适碳源、氮源的质量分数和菌龄,同时选取发酵时间、初始pH值、接种菌体量和装液量4个因子进行正交试验.最终得到的最优条件:胶体几丁质质量分数为0.8%,酵母粉质量分数为1.0%,菌龄为12h,发酵时间为72h,初始pH值为8.5,菌体干质量为90mg,装液量为20mL.在此条件下,酶活力可达17.020μkat.L-1.另外,在二步发酵工艺中添加0.1%纤维素,酶活力可提高至18.804μkat.L-1,比一步发酵提高1.27倍.更多还原

【Abstract】 Two-step fermentation was used to investigate the fermentation conditions of chitinase production by Serratia marcescens.The optimum bacterial age and the concentrations of carbon source and nitrogen source in the two-step fermentation were obtained through single factor method.At the same time,fermentation time,initial pH value,bacterial dose and loadage were selected as objects with orthogonal design.The chitinase activity reached 17.020 μkat·L-1 under the optimized condition: colloidal chitin 0.8%,yeast extract 1.0%,baceria age 12 h,incubation time 72 h,initial pH 8.5,bacteria dry weight 90 mg,loadage 20 mL in 250 mL conical flask.By adding 0.1% cellulose to two-step fermentation,activity of chitinase was 18.804 μkat·L-1 that was 1.27 times higher than that of one-step fermentation.更多还原