碱性脂肪酶高产菌株yz-145的筛选及产酶条件

Mutation breeding of an alkaline high-yield lipase strain yz-145 and study of fermentation conditions

从蚕茧浸渍腐化水中分离获得一株产碱性脂肪酶菌株,通过紫外线和硫酸二乙酯多次诱变,选育出一株高产菌株yz 145。该菌株经发酵研究表明,其最适培养基为:蚕蛹粉5%,蔗糖1.0%,橄榄油0.5%,(NH4)2SO40.5%,MgSO4·7H2O0.2%,K2HPO40.05%。最佳产酶条件:初始pH9.0～9.5,30℃培养48h,产碱性脂肪酶活力高达1615U/ml。经5代培养,该菌株产酶活力稳定,并对其酶的性质进行了研究。

A strain producing alkaline lipase was isolated from sewage of soaked silkworm cocoons and multi-mutated by ultraviolet ray and diethyl sulfate.A high-yield strain yz-145 was obtained.The optimal culture medium for the strain enzyme consisted of 5% silkworm chrysalis powder , 1.0% sugar, 0.5% olive oil, 0.5% (NH_4)_2SO_4, 0.2% MgSO_4·7H_2O,and 0.05% K_2HPO_4. The optimal fermentation conditions were initial pH 9.0-9.5, culture time 48 h, and culture temperature 30℃. The enzyme activity reached 1615 U/ml under this culture condition. The results of inspecting the strain through five generation cultures showed that the enzyme activity of the strain was stable. Meanwhile, the characteristics of the alkaline enzyme of the strain were also studied.