Abstract:

Avermectin is a macrolide compound produced through fermentation by S.avermitilis, and its a kind of widely used biological pesticide. This paper investigated the function of maltose transporter system and the relation between the expression of maltose transporter system and the yield of avermectins in S.avermitilis. The malEFG gene was amplified by PCR using genomic DNA of S. avermitilis as template, and then was inserted into multi\|copy vector and integration vector, respectively. Each expression vector was transformed into S. avermitilis ATCC31267 and GB\|165, respectively. The resulting transformants were cultured in fermentation medium to study the effect of malEFG overexpression on avermectin biosynthesis. The yield of avermectin was increased by 3~3.2 fold in ATCC31267 and by 40%~60% in GB\|165 after the malEFG gene being overexpressed in them compared to that of parent strain.

Key words: avermectin, Streptomyces avermitilis, maltose, malEFG gene expression

摘要：

阿维菌素是由阿维链霉菌(Streptomyces avermitilis)发酵产生的大环内酯类化合物，是一种应用广泛的生物农药。对阿维链霉菌中麦芽糖转运系统基因的表达量对阿维菌素合成的关系进行了初步研究。克隆malEFG基因至链霉菌整合型和多拷贝表达载体，分别转化阿维链霉菌野生型菌株ATCC31267和阿维菌素高产菌株GB165中，结果不同的阿维链霉菌转化子阿维菌素的产量都有一定程度的提高。野生型菌株阿维菌素转化子的产量是出发菌株的3~3.2倍，高产菌株的转化子阿维菌素的产量提高了40%~60%。

关键词: 阿维菌素；阿维链霉菌；麦芽糖；malEFG基因表达