Monday, August 2, 2010
Pacific Concourse (Hyatt Regency San Francisco)
Corynebacterium glutamicum, a high-GC Gram-positive bacterium, is widely used for the industrial production of amino acids. In many bacteria, various sugars are taken up by the phosphoenolpyruvate: carbohydrate phosphotransferase system (PTS). Elucidation of the function and regulation of PTS in C. glutamicum is of great interest in improvement of its sugar utilization. Previously, we reported a C. glutamicum R beta-glucoside PTS encoded by bglF. Here we report that C. glutamicum R encodes an additional beta-glucoside PTS gene, bglF2, organized in a cluster with putative phospho-beta-glucosidase, bglA2, and putative antiterminator, bglG2. While single gene disruption strains of either bglF or bglF2 can utilize salicin or arbutin as sole carbon sources, a double disruption strain exhibited defects in salicin and arbutin utilization. Expression of both bglF and bglF2 is induced in the presence of salicin or arbutin, though disruption of bglG2 affects only bglF2 expression. Moreover, in the simultaneous presence of glucose plus salicin or glucose plus arbutin, glucose strictly represses the expression of bglF but not much that of bglF2. We conclude that BglF and BglF2 have a redundant role in beta-glucoside transport, but the catabolite repression control of the two bgl genes is varied.
This work was partially supported by a grant from the New Energy and Industrial Technology Development Organization (NEDO).