Toxicity and degradation of metal-complexed cyanide by a bacterial consortium under sulfate-reducing conditions.
Free cyanide at 1 mm decreased the initial sulfate reduction rate of a batch culture of granular sludge from 0.3 to 0.14 mmol d(-1) g(-1) SS (suspended solid), whereas 0.5 mm cyanide had a minimal effect (0.25 mmol d(-1) g(-1) SS). The order of toxicity of metal-complexed cyanides to the sludge was as follows: zinc-complexed cyanide (most toxic) > free cyanide = nickel-complexed cyanide > copper-complexed cyanide (least toxic), which also corresponds well with the order of the stability (dissociation) constants of the metal-cyanide complexes. A consortium degrading cyanide was enriched using nickel cyanide as the sole nitrogen source. This consortium completely removed 0.5 mm of nickel-complexed cyanide under sulfate-reducing conditions in 11 d. Analysis of clone library of 16S rRNA genes shows that the consortium was composed of three major phylotypes including Desulfovibrio.
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
Zhe-Xue
ZX
Quan
Jin-Woo
JW
Bae
Sung-Keun
SK
Rhee
Yong-Gyun
YG
Cho
Sung-Taik
ST
Lee
D001421:Bacteria, Anaerobic / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D003486:Cyanides / Q000493:pharmacokinetics* / Q000494:pharmacology; D003901:Desulfovibrio / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D008670:Metals / Q000493:pharmacokinetics* / Q000494:pharmacology; D010084:Oxidation-Reduction; D012722:Sewage / Q000382:microbiology*; D013431:Sulfates / Q000378:metabolism*
D003486:Cyanides; D008670:Metals; D012722:Sewage; D013431:Sulfates