嗜热链球菌胞外多糖生物合成的研究进展

Research advance in the exopolysaccharide biosynthesis of Streptococcus thermophilus

嗜热链球菌是一种公认的安全性益生菌,作为重要的食品发酵剂,广泛应用在发酵乳和奶酪等食品工业生产中,在发酵过程中起着重要的作用,日益成为食品科学研究的热点之一。由于与其他微生物菌株相比安全性高,目前在医药保健等行业中也有着广泛的应用。在嗜热链球菌代谢产物研究中,胞外多糖(exopolysaccharide,EPS)因独特的理化特性和生理功能而备受研究者青睐。嗜热链球菌来源的EPS不但具有降低胆固醇、抗肿瘤和促进肠道粘附等生理功能,而且还能够作为食品添加剂和稳定剂显著改善食品物性。本文重点介绍了嗜热链球菌EPS的生物合成、EPS合成基因簇及其代谢调控,期望为嗜热链球菌EPS生物合成的深入研究提供参考。

Streptococcus thermophilus is recognized as ‘‘generally recognized as safe’’ probiotic and widely used as an important food starter in food industry production such as fermented milk and cheese.Owing to the important function of S.thermophilus in the fermentation process,it has become one of the hot spots in the research of food science.Because of its high safety compared with other microbial strains,S.thermophilus has also been widely used in the industry of medicine and health care.In the metabolite studies of S.thermophilus,exopolysaccharide(EPS) is favored for its unique physical and chemical properties and physiological functions.EPS produced from S.thermophilus not only has the physiological functions of lowering cholesterol,anti-tumor and promoting intestinal adhesion,but also can significantly improve food properties as a food additive and stabilizer.This review focused on EPS biosynthesis of S.thermophilus,EPS biosynthetic gene cluster and its metabolic regulation,in order to provide reference for studying EPS biosynthesis of S.thermophilus.