Formation of Cysteine Desulfhydrase by Bacteria

Abstract

The distribution of cysteine desulfhydrase activity was studied with crude extract from various bacteria. The enzyme activity was found in strains belonging to Enterobacteriaceae. A bacterial strain isolated from soil and identified as Aerobacter aerogenes I-3-2 had shown markedly high activity.

Cultural conditions for the formation of the enzyme were studied with this strain. l-Cysteine or l-cystine, is essential as an inducer for the enzyme formation. Addition of glycerol at 0.1~0.2% concentration and CaCl₂·2H₂O at 0.2% promoted the enzyme formation. Cell extract with high enzyme activity was prepared from cells grown at 30°C for 8 hr in a medium containing 0.2% l-cysteine·HCl·H₂O, 0.1% glycerol, 0.2% CaCl₂·2H₂O, 0.3% yeast extract, 0.5% meat extract, 0.5% polypepton and 0.2% NaCl in tap water with the pH 7.5.