乳酸链球菌素的分子结构、抗菌活性及基因工程研究

乳酸链球菌素(Nisin)是一种由34个氨基酸组成的天然抗菌素,对革兰氏阳性菌具有广谱抑菌作用。Nisin通过吸附于细胞膜,在膜上形成孔洞杀菌。Nisin的11个基因形成基因簇,负责其翻译后修饰、转运,先导序列的切除,成熟分子的外泌,合成过程的调节等。Nisin高产菌株的选育主要通过物理化学诱变,基因工程高效表达技术的研究刚刚开始。Nisin在食品和医药领域具有广泛的应用。本文主要就Nisin的分子结构、分泌机制、抗菌活性、作用机理,特别是它的基因工程技术研究进展等作一概述。

The Molecular Structure , Antibiotic Activties and Genetic Engineering of Nisin

Nisin is a ribosomally synthesized 34-residue polypeptide which is primarily against a wide range of gram-positive bacterium species.By adhering to the cytoplasmic membrane of sensitive bacteria,Nisin forms pores in the cytoplasmic membrane and lead to the death of sensitive bacteria.The eleven genes nisABTCIPRKFEG form gene cluster,except the structural gene nisA,the others are involved in the intracellular posttranslational modification reactions(nisBC), export(nisT),and extracellular proteolytic activation(nisP) and extrusion.The screen and cultivation of high yield nisin-producing species were obtained mainly by treatment with physical and chemical factors,and researches on the high-efficient extra gene expressing technology are on the starting stage. Nisin has been extensively studied used on dairy food production,meat procession,vegetables and fruit preservation,as well as medicinal fields.This review covers the molecular structure,secretion mechanism,antibiotic activity and the mechanisms involved,and especially the genetic engineering technology of Nisin.