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.
Quan
Zhe-Xue
ZX
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
Bae
Jin-Woo
JW
Rhee
Sung-Keun
SK
Cho
Yong-Gyun
YG
Lee
Sung-Taik
ST
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