Enzymatic study on acetanilide p-hydroxylase in Streptomyces fradiae

S. fradiae exhibited the highest acetanilide p-hydroxylation activity among the Streptomyces spp. Studies with inhibitors (metyrapone, 2,6-dichloroindophenol, α,α′-dipyridyl, o-phenanthroline) and an absorption peak after CO treatment suggested that S. fradiae hydroxylase activity was due to cytochrome p-450. This hydroxylase activity was increased to ten times in the cell extract containing 0.5 mM sodium azide. Further-more, the sedimentary activity in 105,000×g centrifugal forces and solubilization of the activity with Triton-X 100 implied that this enzyme was membrane bound monooxygenase. pH Optimum of the enzyme was 6.5 in membrane bound state.