Inhibition of carotenoid hydroxylation in Staphylococcus aureus by mixed-function oxidase inhibitors

Compounds known to be inhibitors of mixed-function oxidase systems inhibited the aerobic synthesis of hydroxylated carotenoids in Staphylococcus aureus U-71. Growth of the cells in the presence of 2-diethylaminoethyl-2,2-diphenyl valerate, 2,4-dichloro-6-phenylphenoxyethylamine, 2,4-dichloro-6-phenylphenoxyethyldiethylamine, and piperonyl butoxide reduced the levels of the rubixanthins found in stationary-phase cells by 75 to 97%. In cells grown with mevalonate-2-(14)C, the turnover rate of phytoene was reduced and the turnover rate of phytofluenol was increased in the presence of these inhibitors. The zeta- and delta-carotenes, which turn over in the absence of the inhibitors, accumulated (14)C in the presence of the inhibitors. This suggested that a mixed-function oxidase was responsible for the aerobic hydroxylation of delta-carotene in S. aureus U-71.