Degradation of tetracyanonickelate (II) by Cryptococcus humicolus MCN2

Kwon, Hyunji

doi:10.1016/s0378-1097(02)00860-1

Cited by 12 publications

(21 citation statements)

References 19 publications

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“…Many previously published reports pointed out the failure in detecting ammonia accumulation due to immediate consumption of ammonia for growth of microorganisms (Kunz et al 1992;Barclay et al 1998;Kwon et al 2002;Kao et al 2003). In contrast, the transient build-up of ammonia in the present study, which was also observed by Harris & Knowles (1983), indicated that the rate of ammonia degradation was much slower in comparison to that of the rate of formation of ammonia.…”

Section: Resultscontrasting

confidence: 68%

“…Formate was not detectable in the biodegradation medium after 18 h of incubation which was presumably due to the action of formate dehydrogenase converting formate to carbon dioxide in the active growth system (Barclay et al 1998;Kwon et al 2002). Formamide was not detected in the culture broth during the whole period of KCN degradation.…”

Section: Resultsmentioning

confidence: 93%

“…The cyanide-degrading activity of Rhodococcus UKMP-5M differed accordingly as the carbon substrate varied. Glucose and maltose readily supported the degradation of 0.1 mM KCN, with the highest cyanide-degrading activity occurring significantly in the presence of glucose (p < 0.05) (Patil & Paknikar 2000;Kwon et al 2002;Kao et al 2003;Ezzi & Lynch 2005;Hossain et al 2005). Poor cyanide utilization by this bacterium in the presence of arabinose was observed which is in line with previously published findings (Adjei & Ohta 1999).…”

Section: Resultsmentioning

confidence: 96%

“…Addition of glucose in the biodegradation medium provided sufficient nutritional condition which simultaneously enabled growth and cell maintenance of Rhodococcus UKMP-5M. Kwon et al (2002) reported glucose as the limiting factor to achieve complete degradation of 65 mM tetracyanonickelate by Cryptococcus humicolus MCN2. In addition, providing the biodegradation medium with 25 mM glucose remarkably accelerated the rate of cyanide degradation by strains of Trichoderma spp.…”

Section: Resultsmentioning

confidence: 97%

“…Additionally, formate and ammonia, the resulting products from these pathways either directly or through formamide can serve as growth substances for microorganisms (Mak et al 2005). Kwon et al (2002) reported a novel yeast strain Cryptococcus humicolus MCN2 which was capable of transforming KCN into formamide and formic acid as transient intermediates and accumulated ammonia as a final product through two-step enzymatic reaction. The primary enzyme, cyanide hydratase transformed cyanide to formamide which was then subsequently degraded to formate and ammonia by amidase based on the equations below:…”

Section: Resultsmentioning

confidence: 99%

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Biodegradation of cyanide by Rhodococcus UKMP-5M

et al. 2013

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A new bacterial strain, Rhodococcus UKMP-5M isolated from petroleum-contaminated soils demonstrated promising potential to biodegrade cyanide to non-toxic end-products. Ammonia and formate were found as final products during growth of the isolate with KCN as the sole nitrogen source. Formamide was not detected as one of the end-products suggesting that the biodegradation of cyanide by Rhodococcus UKMP-5M may have proceeded via a hydrolytic pathway involving the bacterial enzyme cyanidase. No growth of the bacterium was observed when KCN was supplied as the sole source of carbon and nitrogen even though marginal reduction in the concentration of cyanide was recorded, indicating the toxic effect of cyanide even in cyanide-degrading microorganisms. The cyanide biodegradation ability of Rhodococcus UKMP-5M was greatly affected by the presence of organic nutrients in the medium. Medium containing glucose and yeast extract promoted the highest growth rate of the bacterium which simultaneously assisted complete biodegradation of 0.1 mM KCN within 24 hours of incubation. It was found that growth and cyanide biodegradation occurred optimally at 30• C and pH 6.3 with glucose as the preferred carbon source. Acetonitrile was used as an inducer to enhance cyanide biodegradation since the enzymes nitrile hydratase and/or nitrilase have similarity at both the amino acid and structural levels to that of cyanidase. The findings from this study should be of great interest from an environmental and health point of views since the optimum conditions discovered in the present study bear a close resemblance to the actual scenario of cyanide wastewater treatment facilities.

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Section: Resultscontrasting

confidence: 68%

Section: Resultsmentioning

confidence: 93%

Section: Resultsmentioning

confidence: 96%

Section: Resultsmentioning

confidence: 97%

Section: Resultsmentioning

confidence: 99%

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Biodegradation of cyanide by Rhodococcus UKMP-5M

et al. 2013

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The current and future applications of microorganism in the bioremediation of cyanide contamination

Baxter

Cummings

2006

Antonie Van Leeuwenhoek

117

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Inorganic cyanide and nitrile compounds are distributed widely in the environment, chiefly as a result of anthropogenic activity but also through cyanide synthesis by a range of organisms including higher plants, fungi and bacteria. The major source of cyanide in soil and water is through the discharge of effluents containing a variety of inorganic cyanide and nitriles. Here the fate of cyanide compounds in soil and water is reviewed, identifying those factors that affect their persistence and which determine whether they are amenable to biological degradation. The exploitation of cyanides by a variety of taxa, as a mechanism to avoid predation or to inhibit competitors has led to the evolution in many organisms of enzymes that catalyse degradation of a range of cyanide compounds. Microorganisms expressing pathways involved in cyanide degradation are briefly reviewed and the current applications of bacteria and fungi in the biodegradation of cyanide contamination in the field are discussed. Finally, recent advances that offer an insight into the potential of microbial systems for the bioremediation of cyanide compounds under a range of environmental conditions are identified, and the future potential of these technologies for the treatment of cyanide pollution is discussed.

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Immobilized cell reactors in mineralization of dicarboxylic acid solid waste

et al. 2006

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Dicarboxylic acid solid waste containing phthalic acid, malic acid, quinone, saturated and unsaturated dicarboxylic esters etc., are discharged in huge quantities during the crackdown of benzene over the catalyst vanadium at temperatures greater than 500 degrees C in a dicarboxylic acid manufacturing industry. Concern over the biological effects of these compounds underlines the necessity to treat this solid waste. The role of yeast Saccharomyces cerevisiae and anaerobic mixed bacterial cultures immobilized in activated carbon, in sequential two stage anoxic reactors, were investigated for the degradation of dicarboxylic acid solid waste (DASW). In the first stage, DASW was dissolved in water to yield a concentration of 0.5% w/v and was treated in yeast Saccharomyces cerevisiae immobilized reactor at an optimum residence time of 24 h. The yeast fermented samples were further treated in an upflow anaerobic reactor containing mixed culture immobilized in activated carbon at an Hydraulic Retention Time (HRT) of 0.2076 days at an hydraulic flow rate of 14.6x10(-3 )m(3)/day and Chemical Oxygen Demand (COD) loading rate of 4.3 kg/m(3)/day. The intermediates that were formed during the yeast fermentation and the anaerobic degradation of DASW were characterized by HPLC, proton NMR, C(13) NMR and mass spectrometry.

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Degradation of tetracyanonickelate (II) by Cryptococcus humicolus MCN2

Cited by 12 publications

References 19 publications

Biodegradation of cyanide by Rhodococcus UKMP-5M

Biodegradation of cyanide by Rhodococcus UKMP-5M

The current and future applications of microorganism in the bioremediation of cyanide contamination

Immobilized cell reactors in mineralization of dicarboxylic acid solid waste

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