产耐高温酸性脂肪酶菌株A-16的诱变选育及其发酵条件优化

Mutation Breeding of Thermostable Acid Lipase-Producing Strain A-16 and Optimizing of Its Lipase-Producing Condition

摘要: 从炼油厂附近土壤中筛选得到一株产耐高温酸性脂肪酶菌株A-16，通过紫外线(UV)和甲基磺酸乙酯(EMS)的复合诱变选育，获得1株产脂肪酶活力较高的突变株UE-03，产脂肪酶活力为17695.6 U/mL，比原始菌株提高了73.6%，将UE-03连续传代培养5次，产酶能力稳定。对突变株UE-03产酶条件进行了探讨，通过单因素试验筛选出最适初始pH4.0，温度为45℃，吐温-80添加量为0.15% w/v；在此基础上采用响应面分析法优化产酶条件，得到适宜产酶条件为：pH 4.28，温度46.8℃，吐温-80添加量0.15% w/v，经优化后菌株产酶活力达到19339.5 U/mL，为该菌株进一步开发利用提供优良菌种和技术参考。

Abstract: A strain A-16 producing thermostable acid lipase was isolated from the soil of the refinery. By using the lipase-producing strain A-16 as starting strain, a mutant strain UE-03 with high activity of lipase were obtained and selected by the compound mutation breeding of ultraviolet (UV) and ethyl methyl sulfonate (EMS), the activity of lipase produced by that strain reached 17695.6 U/mL, and it was about 73.6% higher than that of the starting strain; the genetic stability experiment showed that the mutant UE-03 had a better genetic stability after 5 times of subculture. The fermentation conditions of mutant strain UE-03 producing lipase were investigated, the optimum results of initial pH 4.0, temperature 45℃, tween-80 0.15% (w/v) were obtained by single-factor test. On this basis, by using response surface methodology to optimize the fermentation conditions, the suitable fermentation parameters were initial pH 4.28, culture temperature of 46.8℃, tween-80 0.15% (w/v), and the acid lipase activity was up to 19339.5 U/mL after optimizing. The study provided ex-cellent strains and technology reference for the further development and utilization of the strain.