摘要
利用分批培养，对乳酸链球菌ＳＭ５２６产生乳链菌肽（ｎｉｓｉｎ）的代谢调控及发酵条件进行研究，代谢动力学分析表明，ｎｉｓｉｎ在ＳＭ５２６指数生长期产生，到指数生长后期达到高峰，进入稳定期ｎｉｓｉｎ逐渐停止产生，表现出一种初级代谢动力学特征。ｎｉｓｉｎ的生物合成主要受碳源、氮源和磷源的调控，试验了各种不同的碳源，发现以二糖为碳源要比以单糖为碳源效果好；在基本发酵培养基中提高碳源（蔗糖）浓度，可使菌体得率和ｎｉｓｉｎ产率同时得以提高，其中以４％（Ｗ／Ｖ）蔗糖浓度较理想。此处碳源的调控主要是通过提高菌体生物量以达到提高ｎｉｓｉｎ效价。磷源则对ｎｉｓｉｎ的生物合成起极大的促进作用，试验了不同的磷源，其中以ＫＨ２ＰＯ４效果最好，在基本发酵培养基中提高ＫＨ２ＰＯ４浓度，可使得在菌体生物量基本不变的情况下，ｎｉｓｉｎ效价大幅度提高。
Nisin production by Streptococcus lactis SM526 was studied in batch fermentation process using a complex medium.Nisin production showed primary metabolite kinetics:nisin biosynthesis took place during the active growth phase and completely stopped when cells entered the stationary phase.Nisin biosynthesis seems to be dependent on carbon source regulation,nitrogen source regulation and phosphate control.A wide variety of carbohydrates had been examined for their abilities to promote both SM526 growth and nisin biosynthesis.Nisin production with disaccharides as carbon substracte was always higher than that obtained with monosaccharides.Higher concentrations of sucrose were tested in fermentation process.Consequently,both the biomass and the nisin yield were improved.Here the further improvement of nisin yield was obtained by generating higher cell densities.However,the inorganic phosphate particularly stimulated nisin formation.The influence of various phosphorous on SM526 growth and nisin production was studied in batch fermentation process.KH2PO4 was found to be best phosphorous for nisin production. Increasing initial phosphate concentration exerted a double effect,creating favourable pH conditions and particularly stimulating the nisin production.
出处
《食品与发酵工业》
CAS
CSCD
北大核心
1996年第3期37-41,共5页
Food and Fermentation Industries
关键词
乳酸链球菌
乳链菌肽
发酵条件
Streptococcus lactis,Nisin,Primary metabolite kinetics
