Regulation of dihydrodipicolinate synthase during growth and sporulation of Bacillus cereus

Abstract

A four to sixfold increase in specific activity of dihydrodipicolinic acid synthase was observed during sporulation of B. cereus. The enzyme from cells harvested before and after the increase in specific activity appeared to be very similar as judged by pH optima, heat denaturation kinetics, apparent Michaelis constants, chromatography on diethylaminoethyl cellulose and Sephadex G200, and polyacrylamide gel electrophoresis. Studies with various combinations of amino acids and one of the enzyme substrates, pyruvate, failed to give evidence for control of the enzyme by activation, inhibition, repression, induction, or stabilization. Omission of calcium from the sporulation medium had no significant effect on the specific activity pattern of the enzyme as a function of age of culture.