The Formation of Keto and Amino Acids by Mycobacterium butyricum Growing in a Chemically Defined Medium

Abstract

SUMMARY : a-Oxoglutaric, pyruvic and amino acids accumulated extracellularly when Mycobacterium butyricum was grown in a chemically defined medium containing glycerol as carbon source and ammonium sulphate as nitrogen source. The excretion of keto acids was diminished and that of amino acids was increased by raising the concentration of ammonium sulphate relative to that of glycerol. This change is consistent with the operation of a citric acid cycle which is performing synthetic functions. The labelling of the somatic amino acids formed in the presence of glycerol and either (14C) bicarbonate or ( W 4 C ) acetate is also consistent with the occurrence of a citric acid cycle.