海洋Arthrobacter protophormiae CDA2-2-2产几丁质脱乙酰酶发酵条件优化

Optimization of Fermentation Conditions for the Production of Chitin Deacetylase from Arthrobacter protophormiae CDA2-2-2

对海洋Arthrobacter protophormiae CDA2-2-2产几丁质脱乙酰酶发酵培养基和发酵条件进行优化,提高发酵产酶水平。在单因素实验优化的基础上,利用PB试验筛选显著影响菌株发酵产酶酶因素,进一步利用响应面法优化这些因素,获得最佳发酵培养基和培养条件。利用单因素实验优化获得碳源、氮源、金属离子、发酵温度、发酵时间、装液量、初始pH和转速的最佳条件。PB试验筛选获得显著影响发酵产酶的因素为MgSO4、发酵温度和葡萄糖。运用Box-Behnken设计,通过响应面法对上述3因素进行优化,获得Arthrobacter protophormiae CDA2-2-2最佳培养基配方为:葡萄糖0.5%,酵母粉1%,MgSO40.015%;发酵条件为:发酵温度38℃,初始pH7.0,转速140 r/min,发酵时间84 h,接种量2%,装液量40%。在此条件下Arthrobacter protophormiae CDA2-2-2产几丁质脱乙酰酶酶活为14.58 U/mL,较优化前提高了2.5倍。本研究结果为Arthrobacter protophormiae CDA2-2-2几丁质脱乙酰酶的进一步开发和应用奠定试验基础。

The fermentation conditions of marine Arthrobacter protophormiae CDA2-2-2 were optimized to enhance the production of chitin deacetylase.Different process variables such as carbon sources,nitrogen sources,temperature,metal ions,time,volume,initial pH,rotate speed,and inoculum size were evaluated by one parameter at-a-time strategy.A significant influence of MgSO4,fermentation temperature and glucose on chitin deacetylase production was noted with Plackett-Burman design.Then,a three-level Box-Behnken design was employed to optimize the medium composition and culture conditions to produce the chitin deacetylase in shake-flask.Using this methodology,the quadratic regression model of producing chitin deacetylase was built and the optimal combinations of media constituents and culture conditions for maximum chitin deacetylase production were determined as MgSO40.01%,fermentation temperature 38℃,glucose 0.57%.Chitin deacetylase production obtained experimentally coincident with the predicted value and the model was proven to be adequate.The optimization of these parameters in flask experiments allowed us to increase the production of chitin deacetylase to 14.58 U/mL,which was increased by 2.5 times than that of before optimization.These results support the potential use of A.protophormiae CDA2-2-2 to produce chitin deacetylase,which would be applied to prepare chitosan with enzymatic deacetylation route.