一株耐热脂肪酶产生菌的鉴定及其脂肪酶基因的克隆

Classification of Thermostable Lipase-producing Bacterium and Cloning of Lipase Gene

目的:从北方堆肥土样中分离、筛选获得产耐热脂肪酶的嗜热菌株FS32b,确定该菌株的分类学地位及其所产耐热脂肪酶基因。方法:通过研究该菌株16SrDNA基因序列的系统进化树,进行菌种分类鉴定并利用PCR技术获得其脂肪酶基因。结果:FS32b与报道过的Bacillus subtilisX60646有紧密的亲缘关系,二者的16S rDNA序列相似性为99%,其脂肪酶基因经序列测定分析表明,该菌株含长度为639bp的耐热脂肪酶基因的完整开放阅读框架(ORF)。此片断编码有213个氨基酸的酶。结论:FS32b初步鉴定为Bacillus subtilis,其脂肪酶基因的克隆为以后高效基因工程菌的构建奠定了基础。

Objective： A lipase - producing strain is isolated from the dunghill soil in the northenm of China, and its phylogenefic position was investigated. Methods： The strain FS32b was identified according to its 16SrDNA gene sequence similarity and DNA fragment encoding lipase was amplified by PCR from genomic DNA. Results：FS32b was closed to Bacillus subtilis X60646 and its 16S rDNA gene sequence 99 % identical with Bacillus subtills X60646. Analysis of sequence detection show that FS32b indudes the Open Read Frame of thermostable lipase gene. This fragment coded the enzyme of 213 amino acid. Conclusion： FS32b was identified and denominated as Bacillus subtills and cloning of its lipase gene, which has laid a foundation of microbial mutation and lipase - producing recombinant strains.