产几丁质酶菌株SWCH-6的筛选、鉴定及其产酶条件的优化研究

Screening, Identification of a Chitinolytic Bacterium Strain SWCH-6 and Its Optimal Chitinase Fermentation Conditions

摘要:

从汕头海湾养殖区域的海底沉积物中分离到1株几丁质酶活性较高的菌株, 命名为SWCH-6, 根据菌株的形态特征、生理生化特征和16S rDNA 序列, 确定该菌株为嗜水气单胞菌(Aeromonas hydrophlilla)。采用单因素优化方法结合正交实验, 得到菌株SWCH-6产几丁质酶的最佳发酵条件：胶体几丁质25.0 g/L, 胰蛋白胨10.0 g/L, 陈海水1.0 L, pH 8.5, 32℃, 150 r/min培养72 h; 在该条件下酶活力达0.39 U/mL。此外, 菌株所产几丁质酶的最适催化pH 5.0; 最适催化温度为40℃; Cu2+、Fe3+及表面活性剂Tween-80能增强该酶的催化活性; Zn2+、Mn2+及表面活性剂SDS、洗衣粉对该酶的催化活性有抑制作用, 与其它几丁质酶存在着一些不同。

关键词:几丁质酶, 嗜水气单胞菌, 优化

Abstract:

A bacterium, having high chitinolytic activity, was isolated from sediment of Shantou Bay, named SWCH-6. According to its physiological and biochemical characteristics and 16S rDNA sequence, it was identified as Aeromonas hydrophlilla. The optimal chitinase fermentation conditions of strain SWCH-6 were conformed by single-factor experiments and orthogonal experiments, they were colloidal chitin 25.0 g/L, tryptone 10.0 g/L, seawater 1 L, pH 8.5, 32℃, 150 r/min for 72 h. In these conditions, its chitinase activity reached 0.39 U/mL. In addition, at 40℃and pH 5.0, its chitinase performed the highest catalytic activity and its chitinase activity could be enhanced by Cu2+, Fe3+ and surfactant toween-80; weakened by Zn2+, Mn2+ and surfactants SDS, detergent powder, and there were some differences from orther chitinases.

Key words:Chitinase, Aeromonas hydrophlilla, Optimization