Cyanide Formation by Chromobacterium violaceum

Abstract

The formation of cyanide by a Chromobacte?ium violaceum strain was studied with growing cultures and with nonproliferating cells grown in complex and chemically defined media. Most of the cyanide was produced during the log-phase growth of the organism, and accumulated in the culture supernatant fluid. A synergistic effect of glycine and methionine on cyanide formation in a chemically defined medium was observed, and the amount of cyanide formed was found to be dependent on the concentrations of the two substances. Cyanide formation by nonproliferating cells was stimulated by preincubation with glycine and methionine. Cyanide formation by adapted cells in the presence of glycine and methionine was stimulated by succinate, malate, or fumarate, and depressed by azide and 2,4-dinitrophenol. Methionine could be replaced by betaine, dimethylglycine, and choline.

Cyanide production by Pseudomonas fluorescens and Pseudomonas aeruginosa

“…The maximum rate of cyanide production by P. fluorescens occurred during the transition from exponential to stationary growth phase. Similar results have been reported for P. aeruginosa (7), an unidentified Pseudomonas species (23), and C. violaceum (14,18).…”

The effect of formation of cyanide as a secondary metabolite on survival ofChromobacterium violaceum

“…In C. violaceum the effect of cyanogenesis on cell viability is more difficult to categorize as advantageous or detrimental. Cultures grown on glutamate alone, which had a low level of cyanogenesis, survived longer than those which had elevated levels of cyanogenesis caused by the addition of the precursor (glycine) and/or the stimulator (methionine) [13,15]. Since cyanogenesis is likely to be due to the need for the bacteria to remove toxic intracellular build-up of glycine and/or methionine [27,28], the addition of these amino acids to the growth medium probably aggravates this situation and, despite the enhanced cyanogenesis, accelerated death occurs.…”

“…Chromobacterium violaceum and some pseudomonads form cyanide as a secondary metabolite [10,11]. Cyanogenesis is stimulated by inclusion of glycine and methionine in the growth medium; glycine is the precursor of cyanide [10][11][12][13][14][15][16][17][18][19]. Cyanogenesis is stimulated by increases in medium iron and phosphate content, although concentrations of phosphate greater than 10 mM also repress cyanide formation by Pseudomonas aeruginosa [ 15,19].…”

Cassava Wastewater and Solid Waste Leachate as Cyanogenic Substrates for the Growth of Nitrile and Linamarin-Utilizing Bacteria

“…In certain ecosystems, cyanogenic microorganisms represent a large part (up to 50%) of the soil microbial community [10]. However, cyanide is formed at early stationery phase during growth only within a short time period [11. A large amount of cyanide formation can be generated only in certain growth media under specific conditions [12,13]. In this connection, this study aims to increase the knowledge base of bioremediation potentials of the nitrile and linamarin-degrading organisms as well as their biodegradation of environmental nitrile-contaminants.…”