Enzymatic Detoxification of Cyanide: Clues from Pseudomonas aeruginosa RhodaneseCipollone R. · Ascenzi P. · Tomao P. · Imperi F. · Visca P.
aDipartimento di Biologia, Università ‘Roma Tre’; bIstituto Nazionale per le Malattie Infettive IRCCS ‘Lazzaro Spallanzani’, Roma, and cDipartimento di Medicina del Lavoro, Istituto Superiore per la Prevenzione e la Sicurezza sul Lavoro, Monteporzio Catone (Roma), Italy
Cyanide is a dreaded chemical because of its toxic properties. Although cyanide acts as a general metabolic inhibitor, it is synthesized, excreted and metabolized by hundreds of organisms, including bacteria, algae, fungi, plants, and insects, as a mean to avoid predation or competition. Several cyanide compounds are also produced by industrial activities, resulting in serious environmental pollution. Bioremediation has been exploited as a possible alternative to chemical detoxification of cyanide compounds, and various microbial systems allowing cyanide degradation have been described. Enzymatic pathways involving hydrolytic, oxidative, reductive, and substitution/transfer reactions are implicated in detoxification of cyanide by bacteria and fungi. Amongst enzymes involved in transfer reactions, rhodanese catalyzes sulfane sulfur transfer from thiosulfate to cyanide, leading to the formation of the less toxic thiocyanate. Mitochondrial rhodanese has been associated with protection of aerobic respiration from cyanide poisoning. Here, the biochemical and physiological properties of microbial sulfurtransferases are reviewed in the light of the importance of rhodanese in cyanide detoxification by the cyanogenic bacterium Pseudomonas aeruginosa. Critical issues limiting the application of a rhodanese-based cellular system to cyanide bioremediation are also discussed.
Dipartimento di Biologia
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Published online: July 28, 2008
Number of Print Pages : 13
Number of Figures : 3, Number of Tables : 3, Number of References : 91
Journal of Molecular Microbiology and Biotechnology
Vol. 15, No. 2-3, Year 2008 (Cover Date: August 2008)
Journal Editor: Saier Jr. M.H. (La Jolla, Calif.)
ISSN: 1464–1801 (Print), eISSN: 1660–2412 (Online)
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