摘要
针对一株从天山一号冰川沉积层中得到的假单胞菌T1-39,优化其产低温脂肪酶发酵条件,研究低温脂肪酶部分酶学性质,采用p-NPP法测定酶活力,设计产酶培养基成分及培养条件。确定产酶培养基成分为:葡萄糖5 g/L、胰蛋白胨5 g/L、(NH4)2SO4 5 g/L、K2HPO4 2 g/L、橄榄油乳化液50 mL/L、MgSO4·7H2O 0.5 g/L。优化后培养条件为250 mL摇瓶装液量为20 mL,培养温度15℃,初始pH为9。在优化发酵条件下,菌株发酵液低温脂肪酶酶活力可达到9.77 U/mL,较优化前(3.14 U/mL)提高了3.11倍。粗酶液最适反应温度为30℃,在60℃处理30 min后仍有40%的酶活,最适pH值为9,Mg2+、Zn2+、Ni2+、Ba2+对粗酶液有激活作用,而Sn2+、Cu2+对酶活均有不同的抑制作用。
A cold adapted lipase producing strain T1-39 was isolated from the sediments of the bottom layer of the glacier No.1 in the Tianshan mountains, China, the enzyme producing conditions and partial properties of enzyme was studied and optimized. The lipase activity was determined with p-NPP methods and gradual optimization of the enzyme producing conditions and fermentation medium. The optimal medium of liquid fermentation for yield of cold-lipase of T1-39 contained glucose 5 g/L, tryptone 5 g/ L, （NH4）2SO4 5 g/L, K2HPO4 2 g/L, olive oil emulsion 50 mL/L, MgSO4·7H2O 0.5 g/L. The strain optimal fermentation condition was that loading volume 20 mL/250 mL, initial pH9, incubated temperature at 15 %. The lipase activity reached 9.77 U/mL, which was 3.11 folds of that before optimization. Properties of the crude enzyme shown by the results, the optimal temperture was 30 ℃, about 40% of the original activity was maintained by heated at 60 % for 30 min, the optimal pH was 9, the enzyme activity was stimulated by Mg^2＋, Zn^2＋, Ni^2＋, Ba^2＋, but was inhibited by Sn^2＋, Cu^2＋.
出处
《食品科技》
CAS
北大核心
2014年第6期7-12,共6页
Food Science and Technology
关键词
假单胞菌
发酵
酶学性质
低温脂肪酶
Pseudomonas
fermentation
enzyme properties
cold-adapted lipase
