Nonmetabolizable arabinose inhibits Vibrio cholerae growth in M9 medium with gluconate as sole carbon source

Abstract

Marine bacterium Vibrio cholerae, belonging to serogroups O1 and O139 are responsible to cause cholera in human. Pentose sugar arabinose is nonmetabolizable by the pathogen and is present in environmental niches as well as in the human intestine. In this study, arabinose mediated V. cholerae growth interference has been assessed in M9 minimal medium containing gluconate as sole carbon source in the light of Entner-Doudoroff (ED) pathway, an obligatory metabolic route for gluconate utilization. V. cholerae O1 and O139 strains failed to grow in presence of ≥0.3% arabinose in M9 with 0.2% gluconate but no growth inhibition in presence of arabinose in M9 with 0.2% glucose. Transcriptional analysis of edd and eda, the genes constituting the ED pathway, showed ~100 and ~17 folds increase, respectively, in M9-gluconate. Minor increase of ~4 and ~2 folds for the edd and eda, respectively, was noted in 0.5% arabinose supplemented AKI. Observed arabinose mediated growth inhibition also contributes to understanding of altered phenotypes, if any, during complementation/expression studies in V. cholerae with PBAD vectors and arabinose as an inducer.