Arginine and Citrulline Catabolic Pathways Encoded by the arc Gene Cluster of Lactobacillus brevis ATCC 367.

摘要: High concentrations of l-arginine or l-citrulline in the growth medium provided wine bacterium Lactobacillus brevis with a significant advantage. The arginine deiminase pathway (ADI) arc gene cluster contains three genes-arcD, arcE1, and arcE2-encoding putative l-arginine/l-ornithine exchangers. Uptake experiments Lactococcus lactis cells expressing genes showed that all transported l-ornithine affinities micromolar range. Similarly, ArcD ArcE2 l-arginine, while ArcE1 l-citrulline, an intermediate ADI pathway. Chase very efficient exchange by ArcE1. Low (millimolar range) combined low translocation rates were found for l-arginine. Resting grown presence rapidly consumed respectively, producing ammonia l-ornithine. About 10% degraded was excreted as l-citrulline. Degradation not subject to carbon catabolite repression glucose medium. At high pH, required induction degradation Pathways are proposed catabolic breakdown merge at level ornithine transcarbamylase l-Arginine uptake is catalyzed and/or ArcE2, l-Citrulline excretion during be through l-arginine/l-citrulline exchange.IMPORTANCELactobacillus brevis, isolated from wine, well other food environments, expresses consists l-citrulline/l-ornithine exchanger part enzymes. pathways provide mechanism accumulation fermented products precursor carcinogen ethyl carbamate.