Identification of Genes Required for Glucan Exopolysaccharide Production in Lactobacillus johnsonii Suggests a Novel Biosynthesis Mechanism.

ABSTRACT: Lactobacillus johnsonii FI9785 makes two capsular exopolysaccharides-a heteropolysaccharide (EPS2) encoded by the eps operon and a branched glucan homopolysaccharide (EPS1). The homopolysaccharide is synthesized in the absence of sucrose, and there are no typical glucansucrase genes in the genome. Quantitative proteomics was used to compare the wild type to a mutant where EPS production was reduced to attempt to identify proteins associated with EPS1 biosynthesis. A putative bactoprenol glycosyltransferase, FI9785_242 (242), was less abundant in the Δeps_cluster mutant strain than in the wild type. Nuclear magnetic resonance (NMR) analysis of isolated EPS showed that deletion of the FI9785_242 gene (242) prevented the accumulation of EPS1, without affecti

SUBMITTER: Mayer MJ 

PROVIDER: S-EPMC7117936 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature