AUTHOR=Song Xin , Xiong Zhiqiang , Kong Linghui , Wang Guangqiang , Ai Lianzhong 

TITLE=Relationship Between Putative eps Genes and Production of Exopolysaccharide in Lactobacillus casei LC2W

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.01882

DOI=10.3389/fmicb.2018.01882

ISSN=1664-302X

ABSTRACT=<p><italic>Lactobacillus casei</italic> LC2W, a probiotic strain, can produce exopolysaccharide (EPS) with anti-hypertensive bioactivity. The relationship between <italic>eps</italic> genes and EPS synthesis in LC2W due to unclear regulation mechanism of EPS biosynthesis was investigated. The several relevant genes in EPS biosynthetic gene cluster were deleted, overexpressed and complemented. The results suggested that glucose-1-phosphate thymidyltranseferase gene (<italic>LC2W_2179</italic>), uncharacterized EPS biosynthesis protein (<italic>LC2W_2188</italic>), and EPS biosynthesis protein (<italic>LC2W_2189</italic>) were related to EPS biosynthesis. EPS titer decreased 15, 13, and 21% when the three genes were deleted, respectively. When they were overexpressed, EPS titer increased 16, 10, and 18%. When they were complemented, EPS titer was similar to the wild-type strain. This work showed the three <italic>eps</italic> genes from LC2W played important roles on EPS production.</p>