EpsA is an essential gene in exopolysaccharide production in Lactobacillus johnsonii FI9785
Küçük Resim Yok
Tarih
2016
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
John Wiley and Sons Ltd
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
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 ?Glcp 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. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.
Açıklama
Anahtar Kelimeler
exopolysaccharide, Article, bacterial gene, bacterial strain, biosynthesis, cell surface, controlled study, EpsA gene, gene deletion, gene expression, gene function, Lactobacillus johnsonii, nonhuman, nuclear magnetic resonance, plasmid, transmission electron microscopy, exopolysaccharide, Article, bacterial gene, bacterial strain, biosynthesis, cell surface, controlled study, EpsA gene, gene deletion, gene expression, gene function, Lactobacillus johnsonii, nonhuman, nuclear magnetic resonance, plasmid, transmission electron microscopy
Kaynak
Microbial Biotechnology
WoS Q Değeri
Q2
Scopus Q Değeri
Q1
Cilt
9
Sayı
4
