摘要
Brevibacterium sp．可以发酵生产胆固醇氧化酶,实验中对该菌种进行了底物诱导及发酵条件的优化, 确定其最适培养基为(%)：蔗糖0．3,酵母膏0．2,蛋白胨0．3,牛内膏0．3,K_2PO_4 0．1,MgSO_4 0．05,pH6．8。最适培养条件为：接种量5%,24℃培养20h,通气量为50mL 培养基/250mL 三角瓶,200r/min。在最适培养基及最适条件下,胆固醇氧化酶的酶活力可达到24．01U/mg,比未优化前1．71U/mg 提高了14倍。该酶具有较强的酸碱稳定性和热稳定性,最适 pH 为6．5,最适温度为54℃。在最适 pH 和温度条件下测得该酶 km 值为7．1 ×10^(-5)mol/L。
Brevibacterium sp. can produce relative high Cholesterol Oxidase （COD）. The optimizad of cultivation conditions was obtained in this paper. The culture medium was 3 g/L sucrose, 2 g/L yeast extract, 3 g/L peptone, 3 g/L beef extract, 1 g/L K2HPO4, 0.5 g/L MgSO4, and 0.2% cholesterol. The initial pH was 6.8 and the inoculum volume was 5 % （V/V）, temperature 24℃, culture time 20h. Under the optimized cultivation elnditions, the enzyme activity reached 2439 U/L and the specific activity reached 24.01 U/mg.
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2006年第2期41-45,共5页
Food and Fermentation Industries
