Control of the synthesis of plasmin-like and plasminogen-activating proteinases in marine bacteria

The biosynthesis of proteinases with various substrate specificities was studied inBacillus firmus 44b andBacillus oligonitrophilus 21p as influenced by the growth conditions and growth phases of the bacteria. The period of the maximum synthesis of plasmin-like enzymes was observed 6 h later than the period of the maximum growth rate ofB. firmus 44b, and 3 h later than the maximum growth rate period ofB. oligonitrophilus 21 p. The periods of the maximum accumulation of activating enzymes were delayed 9 and 12 h, respectively, as compared to the periods of rapid growth of these two bacteria. Catabolite repression of proteinase synthesis and stimulation of the latter with substrate proteins were insignificant. The production of both plasmin-like and plasminogen-activating enzymes was most sensitive to repression by nitrogen deficiency. The production of plasminogen-activating proteinases was less dependent on the carbon source than the production of plasmin-like enzymes.