产几丁质脱乙酰酶海洋细菌的筛选鉴定及产酶条件优化

从海洋样品中筛选产几丁质脱乙酰酶的细菌，对高产菌株进行鉴定，并利用响应面法优化其发酵条件。结果表明，利用添加硝基乙酰苯胺的平板，根据黄色变色圈从海州湾海域海泥样品中筛选获得一株产几丁质脱乙酰酶的细菌MCDA3-3。通过形态学、生理生化特征以及16S rDNA序列分析，将该菌株鉴定为海洋硝酸盐还原菌（Nitratireductor aquimarinus）。利用单因素和响应面法优化菌株MCDA3-3发酵产酶培养基和培养条件，获得最佳发酵培养基配方为木薯淀粉1.1%，玉米浆1.0%，FeCl3·6H2O 0.045%，陈海水配制，pH 5.7；最佳发酵条件为接种量4%，30 ℃、180 r/min发酵48 h。在此条件下酶活为4.07 U/mL，是优化前的2.3倍。

Screening,identification and enzyme production conditions optimization of chitindeacetylase-producing marine bacteria

The chitin deacetylase-producing bacteria were screened from marine samples, the high yield strain was identified, and the fermentation conditions were optimized by response surface methodology. According to yellow circle on a plate with nitroacetanilide, a chitin deacetylase producing bacterium MCDA3-3 was obtained from marine mud samples in Haizhou bay, and was identified as Nitratireductor aquimarinus by morphological, physiological and biochemical characterizations and 16S rDNA sequence analysis. The enzyme production fermentation medium and fermentation conditions were optimized by single factor and response surface methodology. The optimal fermentation medium was cassava starch 1.1%, corn syrup 1.0%, FeCl3·6H2O 0.045%, aged seawater preparation, pH 5.7. The optimal fermentation condition was inoculum 4%, fermentation temperature 30 ℃, rotating speed 180 r/min, and time 48 h. Under the optimal conditions, the enzyme activity was 4.07 U/ml, which was 2.3 times that before optimization.