Compartmentalization of metabolism in Bacillus thuringiensis

Abstract

The compartmentalization of metabolism and the influence of amino acids and various substrates on the growth of Bacillus thuringiensis were studied. Carbon and nitrogen metabolism are compartmentalized only during vegetative growth when glucose is present in the medium, and it is pH-dependent. Organic nitrogen sources or compounds which can generate NADPH for incorporation of ammonium into glutamate were required for growth, sporulation, and crystal formation in minimal glucose-salts medium, designated BM. Abundant growth occurred when organic nitrogen sources such as glutamate, glutamine, arginine, proline, citrulline, ornithine, histidine, aspartate, and asparagine were utilized as the sole sources of carbon and (or) nitrogen at O.OIM concentration. Other organic nitrogen sources able to support growth as carbon and (or) nitrogen sources at equimolar concentrations were alanine, valine, leucine, serine, methionine, lysine, and isoleucine, but growth was less. Serine and gamma-aminobutyric acid (an NADPH generator) supported growth only as the sole sources of carbon. Also pyruvate, alphaketoglutarate, and citrate (an NADPH generator) supported growth of the organism as sole sources of carbon. Succinate, isocitrate, betahydroxybutyrate, and glyoxylate did not support growth as carbon and (or) nitrogen sources. A proposed scheme of the pathway for breakdown of these metabolites in B. thuringiensis is presented.