诱变选育脂肪酶高产菌株及其脂肪酶固定化  

Induced Mutagenesis of High Lipase Productivity Strain and Immobilization of Produced Lipase

作　　者：夏葵[1] 曾虹燕[1] 姜和[1] 蔡联辉[1] 黄理[1] 

机构地区：[1]湘潭大学化工学院生物技术研究所,湘潭411105

出　　处：《中国生物工程杂志》2009年第5期88-94,共7页China Biotechnology

基　　金：湖南省教育厅资助项目(06C816)

摘　　要：以紫外和微波复合诱变选育脂肪酶产生菌Rhizopus sp.RXF12,获得高产突变株RZ13,其脂肪酶摇瓶发酵单位是出发株的2.62倍。菌株经多次传代,遗传性状稳定。对RZ13菌株的发酵条件进行了正交优化,在25℃、pH8.0的条件下,接入5%(v/v)的RZ13菌株单孢子悬液(107个/ml)振荡培养84h,达到RZ13菌株最佳产酶状态,脂肪酶活可达95.08U/ml。考察了脂肪酶性质,在低于40℃,pH7.0～9.0范围内脂肪酶活稳定。经载体筛选及固定化过程优化,选用镁铝水滑石25℃吸附4h,对RZ13脂肪酶进行了固定化。结果表明,固定化酶的最适作用温度为35～55℃,pH为7.5～9.0,较游离酶的均有较大扩展。A mutant strain RZ13 with high lipase productivity was obtained through treating the Rhizopus sp. RXF12 by UV and microwave, and its activity was 2.62-fold of the original one. The high lipase productivity of the mutant strain could be inherited after repetitious subcultures. The optimal culture conditions of the RZ13 for producing lipase were studied. The lipase with highest activity （67.32U/ml） was obtained on the conditions of 25℃, pH 8. 0, 5 % （v/v） single spore suspension （1 × 10^7spore/ml） and 120 r/min for 84h, and stable under 40℃ and pH 8.5. In addition, the lipase was immobilized by adsorption onto Mg-A1 hydrotalcite at 25~C for 4 h by screening carriers and optimizing the immobilization. The results showed that the optimal reaction temperature and pH were 35 -55℃ and 7.5 -9.0, respectively, much wider than the free lipase.

关 键 词：脂肪酶 紫外线 微波 固定化 水滑石 

分 类 号：Q814.2[生物学—生物工程]