壳聚糖酶产生菌筛选及产酶培养优化

以胶体壳聚糖为唯一碳源和DNS酶活鉴定法从烟台近海土壤中分离得到一株高产壳聚糖酶菌株,初步鉴定为白色链霉菌.经发酵培养组分与条件优化,获得最佳培养组分(g.L-1):葡萄糖55,壳聚糖0.5,胰蛋白胨1,尿素8,(NH4)2SO42,NH4Cl 1,KH2PO43,FeSO4·7H2O 1,ZnSO4·7H2O 2,CaCl2·6H2O2,MnSO4·H2O2,NaCl2.最适产酶pH 7.0,温度28℃,装液量50 mL,接种量2%.优化后菌株培养48 h时产酶量为51.65 U.mL-1.

Strain Screening and Optimization of Fermentation Conditions for Producing Chitosanase

A high-yield strain of chitosanase is screened from the soil samples collected from Zhifudao （Yantai, China）, which is obtained with colloidal chitosan as only C-source and determination of chitsanase activity, and then identified as Streptomyces albus. By optimization of medium compositions and culture conditions for chitosanase production, the optimal concentration for higher production of chitosanase are determined as follows： 55 g · L-1 glucose, 0. 5 g · L-1 chitosan, 1 g ·L-1 peptone,2 g · L-1 （NH,）2SO4, 8 g · L-1 urea,1g · L-1 NHaC1, 3 g · L-1 KH2PO4, 1 g · L-1 FeSO4· 7H20, 2 g ·L-1 ZnSO4· 7H20, 2 g · L-1 CaC12 · 6H20, 2 g · L-1 MnSO4· H20 and 2 g · L-1 NaC1. The maximum activity of chitosanase obtained is 51.65 U · mL-1 at 28℃, pH 7.0, 2% inoculum and 50 mL fermentation medium in Erlenmeyer flask （500 mL） for 48 h.