Identification and functional characterization of a fructose-inducible phosphotransferase system in Azospirillum brasilense Sp7

Plant growth promoting rhizobacterium Azospirillum brasilense Sp7 utilizes fructose efficiently via a fructose phosphotransferase system (Fru-PTS). Its genome encodes two putative Fru-PTS, each consisting of FruB (EIIA), FruK (Pfk) and FruA (EIIBC) proteins. We compared the proteomes of A. brasilense Sp7 grown with malate or fructose as sole carbon source, and observed upregulation of component proteins of Fru-PTS1 and several proteins involved in the biogenesis of the type 6 secretion system (T6SS) only on fructose.