RT Journal Article SR Electronic(1) A1 Bowden, G A1 Mothibeli, M. A A1 Robb, F. T A1 Woods, D. R.YR 1982 T1 Regulation of Hut Enzymes and Extracellular Protease Activities in Vibrio alginolyticus hut Mutants JF Microbiology, VO 128 IS 9 SP 2041 OP 2045 DO https://doi.org/10.1099/00221287-128-9-2041 PB Microbiology Society, SN 1465-2080, AB The production of alkaline protease, collagenase and histidine utilization (Hut) enzymes by Vibrio alginolyticus wild-type, hutH1 and hutU1 strains was investigated. Alkaline protease synthesis was stimulated by histidine and urocanic acid in the wild-type and hutU1 strains. In the hutHl mutant alkaline protease production was stimulated by urocanic acid and not by histidine. The Hut enzymes in the wild-type strain were coordinately induced by histidine. Urocanase and forimino-hydrolase were induced by histidine in the hutH1 mutant which lacked histidase and was not able to convert histidine to urocanic acid. Collagenase production in peptone medium was inhibited in the hut mutants. It is concluded that in V. alginolyticus urocanic acid regulates alkaline protease synthesis but that the Hut enzymes are induced by histidine. The involvement of the Hut genetic system in the regulation of alkaline protease and collagenase synthesis is discussed., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-128-9-2041