EpsA is an essential gene in exopolysaccharide production in Lactobacillus johnsonii FI9785

Enes Dertli, Melinda J. Mayer*, Ian J. Colquhoun, Arjan Narbad

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

34 Citations (Scopus)

Abstract

Lactobacillus johnsonii FI9785 has an eps gene cluster which is required for the biosynthesis of homopolymeric exopolysaccharides (EPS)-1 and heteropolymeric EPS-2 as a capsular layer. The first gene of the cluster, epsA, is the putative transcriptional regulator. In this study we showed the crucial role of epsA in EPS biosynthesis by demonstrating that deletion of epsA resulted in complete loss of both EPS-1 and EPS-2 on the cell surface. Plasmid complementation of the epsA gene fully restored EPS production, as confirmed by transmission electron microscopy and nuclear magnetic resonance (NMR) analysis. Furthermore, this complementation resulted in a twofold increase in the expression levels of this gene, which almost doubled amounts of EPS production in comparison with the wild-type strain. Analysis of EPS by NMR showed an increased ratio of the heteropolysaccharide to homopolysaccharide in the complemented strain and allowed identification of the acetylated residue in EPS-2 as the (1,4)-linked βGlcp unit, with the acetyl group located at O-6. These findings indicate that epsA is a positive regulator of EPS production and that EPS production can be manipulated by altering its expression.

Original languageEnglish
Pages (from-to)496-501
Number of pages6
JournalMicrobial Biotechnology
Volume9
Issue number4
DOIs
Publication statusPublished - 1 Jul 2016
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Fingerprint

Dive into the research topics of 'EpsA is an essential gene in exopolysaccharide production in Lactobacillus johnsonii FI9785'. Together they form a unique fingerprint.

Cite this