紫外诱变选育脂肪酶高产菌株及其酶学性质的研究

Mutation Breeding of High-yield Lipase Strains and Study of Properties of Lipase

目的：初步筛选脂肪酶高产菌株。方法：以1444粗壮假丝酵母作为出发菌株，对其进行紫外线诱变育种。结果：经紫外诱变的重复处理、摇瓶复筛和遗传稳定性实验，最终得出两株高产酶突变株Z6及Z8，其酶活分别为22．6、25U／ml，酶活力较出发菌株分别提高了120％和150％。酶学性质研究表明：Z6、Z8的最适反应温度分别为45、50℃，最适pH都为8，在pH6～9较稳定。Z6、Z8的热稳定都较好，在50℃下保温60min酶基本不失活。结论：经紫外诱变获得的突变株Z6及Z8有进一步的研究价值。

Objective： Taking 1444 muscular Gandida mycoderma as initial strain, mutated with UV in order to obtain mutants with high lipase production. Methods： After repetition of UV mutation, screening and gene stability assay of mutants, two strains,Z6,Z8 were finally obtained. Results： Their enzyme activity were 22.6, 25 U/ml respectively, separately increased by 220% and 250% respectively. The optimal pH and temperature of lipase of 7.6 were pH 8.0 and 45℃ respectively. The optimal pH and temperature of lipase of Z8 were pH 8.0 and 50℃ respeclively . Activity of lipase of 7.6 and Z8 were no much change in 50℃ for 60minutes, and stable from pH 6.0 to pH 9.0.