耐有机溶剂蛋白酶产生菌Bacillus cereus WQ9-2发酵条件及酶学性质  

Optimum fermentation conditions and enzymatic properties of organic solvent tolerant protease from Bacillus cereus WQ9-2

作　　者：许家兴[1] 李振东[1] 承龙飞[1] 何冰芳[1] 

机构地区：[1]南京工业大学生物与制药工程学院,南京210009

出　　处：《生物加工过程》2012年第6期7-11,共5页Chinese Journal of Bioprocess Engineering

基　　金：国家高技术发展计划(863计划)资助项目(2006AA02Z202);江苏省普通高校研究生科研创新计划资助项目(CX10B_176Z)

摘　　要：以蜡状芽孢杆菌Bacillus cereus WQ9-2为产耐有机溶剂蛋白酶的出发菌株,对其产酶条件进行优化并初步研究了其酶学性质。在单因素实验基础上,通过中心复合实验确定了产酶的最佳发酵条件为酵母粉8 g/L,葡萄糖17 g/L,KH2PO40.5 g/L,无水MgSO40.3 g/L,CaCl20.5 g/L,NaCl 1.0 g/L;pH 7.5。实验中发现采用低温发酵能大大缩短菌体产酶周期;通过优化发酵时间由最初84 h缩短到48 h,最高比酶活为3 921 U/mL。金属离子螯合剂1,10-菲罗啉(1,10-phenanthroline)、乙二胺四乙酸(EDTA)对该酶有较强的抑制作用,表明该酶可能为金属蛋白酶;Ca2+对该酶的活力及热稳定性有显著提高作用。In order to raise protease production, culture conditions for Bacillus cereus WQ9-2 with the ability to produce organic solvent tolerant protease were optimized by central composite design method. The optimized fermentation conditions were as follows： yeast powder 8 g/L, glucose 17 g/L, KH2PO4 0. 5 g/L, MgSO4 0. 3 g/L, CaC12 0.5 g/L, NaCI 1.0 g/L, and pH 7.5. The cultivation conditions were 25 ~C , and 180 r/rain. Under the optimal conditions for 48 h, the maximum protease production was 3 921 U/mL. The protease activity was activated in the presence of Ca2＋, and inhibited in the presence of EDTA and 1,10-phenanthroline. The results showed that it might be metalloprotease.

关 键 词：BACILLUS CEREUS 耐有机溶剂蛋白酶 优化 酶学性质 

分 类 号：Q814[生物学—生物工程]