Comparative genomics reveals a widespread distribution of an exopolysaccharide biosynthesis gene cluster among Vibrionaceae

Abstract

Objectives: The eps locus in Vibrio diabolicus is involved in the production of the biotechnologically valuable HE800 EPS. In this study, the distribution and diversity of similar eps gene clusters across Vibrionaceae and its variability in relation to phylogenetic relationship were investigated. The aim was to provide a better knowledge of the eps gene cluster importance and to facilitate discovery of new EPS with potent interesting bioactivities. Results: Seventy percent of the 103 genome sequences examined display such an eps locus with a high level of synteny. However, genetic divergence was found inside some monophyletic clades or even between some strains of the same species. It includes gene insertions, truncations, and deletions. Comparative analysis also reveals some variations in glycosyltransferase and export systems genes. Phylogenetic analysis of the Vibrionaceae eps gene clusters within Vibrionaceae suggests a vertical transfer by speciation but also pinpoints rearrangement events independent of the speciation.