INDUCTION OF MALEATE HYDRATASE IN PSEUDOMONAS PSEUDOALCALIGENES

Maleate hydratase (malease, EC 4.2.1.31) activity in P, pseudoalcalige nes is induced when grown on 3-hydroxybenzoate. The specific malease a ctivity was constant during the logarithmic phase in a batch culture c ontaining 3-hydroxybenzoate as the carbon source, when 3-hydroxybenzoa te-grown cells were used as inoculum. When yeast extract-grown cells w ere used as inoculum, the specific malease activity was correlated wit h growth. In both instances the specific malease activity dropped rapi dly as soon as growth ceased. Maleate did not serve as a growth substr ate for this microorganism, but a mutant able to grow on maleate was s elected. The specific malease activity of maleate-grown cells of this mutant was not higher than the basal level of induction of malease act ivity.