海洋芽孢杆菌B-9987中macrolactin生物合成基因簇分析及反式酰基转移酶高表达

目的 对海洋芽孢杆菌B-9987中macrolactin生物合成基因簇及其关键基因进行分析、鉴定及功能研究。方法 通过生物信息学手段对基因簇的基因组成和功能结构域进行了分析；构建了用于酰基转移酶基因高表达的大肠杆菌—芽孢杆菌穿梭载体,采用电击转化方法导入B-9987之中进行高表达。 结果 macrolactins是由位于同一个操纵子的8个基因bmmA-I所编码的反式酰基转移酶聚酮合酶体系组装而成,反式酰基转移酶(trans-acyltransferase,trans-AT)BmmA的高表达使macrolactin A的产量提高了约0.6倍。结论 macrolactin生物合成基因簇在具有生物防治活性的芽孢杆菌中普遍存在,且高度保守；反式酰基转移酶的高表达能够增加macrolactin A的产量。

Characterization of macrolactin gene cluster from Bacillus marinus B-9987 and overexpression of trans-acyl transferase

Objective To identify and characterize the macrolactin gene cluster from Bacillus marinus B-9987. Methods By elaborate bioinformatics analysis, the gene organization and functional domain composition of the macrolactin gene cluster were predicted; to overexpress the trans-acyltransferase (trans-AT) gene, an E. coli-Bacillus shuttle vector was constructed and introduced into B. marinus B-9987 by electroporation. Results Macrolactins are assembled via an trans-AT polyketide synthase system, which is encoded by 8 genes, bmmA-I, located in an operon; overexpression of trans-AT BmmA led to improved macrolactin A production by about 0.6-fold. Conclusion Macrolactin biosynthetic gene clusters are highly conserved among biocontrol Bacillus strains; overexpression of trans-acyl transferase BmmA is able to increase macrolactin A production.