摘要
旨在构建一种在兽疫链球菌(Streptococcus equi subsp.zooepidemicus)中可用的基因诱导表达系统,并探究其在两步发酵中的应用。分别构建蔗糖、乳糖、木糖和乳酸链球菌素(nisin)诱导表达载体,以编码透明质酸合成酶的has A基因作为报告基因,以has A基因功能缺失导致荚膜缺陷的?has A作为宿主菌,观察诱导后荚膜生成情况验证系统的可行性。结果显示,木糖和nisin系统不能诱导has A表达,乳糖系统诱导表达效率低,蔗糖系统可严谨且高效诱导基因表达。以?has A/p LH201菌株实施两步发酵,葡萄糖为唯一糖源时仅用于菌体生长,添加蔗糖诱导产生透明质酸,终产量达到3.4 g/L。成功构建了一种以蔗糖为诱导物的可控-诱导基因表达系统,可用于兽疫链球菌两步发酵。
This work aimed at establishing an inducible gene expression system in Streptococcus zooepidemicus,and investigating theapplication of it in controllable two-stage fermentation. Induced expression vectors by sucrose,lactose,xylose and nisin were constructed,then using has A of hyaluronic acid（HA）synthase as reporter gene,and ？has A with capsule-deletion resulted from the function deletionof gene has A as the host bacterium,the feasibility of these systems was verified by observing the generation of capsule. The results showedthat ：The expression of has A was not induced in the xylose and nisin vector,at low-efficiency in lactose vector,and efficient and rigorous insucrose vector. A controllable two-stage fermentation mode was conducted using Δhas A/p LH201 as strain and glucose only as sole sugar sourcefor the growth of bacteria,and added sucrose induced the generation of HA,and HA production reached at 3.4 g/L. In conclusion,this studysuccessfully constructed a sucrose-induced gene expression system that can be used for two-stage fermentation of S. zooepidemicus.
出处
《生物技术通报》
CAS
CSCD
北大核心
2016年第12期130-136,共7页
Biotechnology Bulletin
基金
天津市国际科技合作项目(13RCGFSY19400)
天津市高等学校科技发展基金项目(20130602)
关键词
兽疫链球菌
可控诱导表达系统
可控两步发酵
透明质酸
Streptococcus zooepidemicus
controlled inducible expression system
controllable two-stage fermentation
hyaluronic acid
