Metabolism of branched-chain amino acids revealed by transcriptome analysis in Vibrio alginolyticus

Branched-chain amino acids (BCAAs) play important roles in nitrogen metabolism. However, little is known about the metabolism of BCAAs in the fish pathogen Vibrio alginolyticus. In this study, the global gene expression patterns of V. alginolyticus ZJ-T cultured in M63 minimal medium supplemented with ammonium sulfate or with three BCAAs (isoleucine, leucine and valine) as nitrogen source were evaluated by transcriptome analysis. The results revealed that 311 genes are up-regulated (| log2(Fold Change)| > 1), which are involved in the pathways of flagellar assembly, bacterial chemotaxis and oxidative phosphorylation etc, and meanwhile 251 genes are down-regulated, which are involved in the pathways of BCAAs biosynthesis, selenocompound metabolism and C5-branced dibasic acid metabolism etc. This study contributes to the understanding of the BCAAs metabolism in the Vibrios.