Vinyl chloride aerobic degradation

The aerobic degradation of chloroethene (vinyl chloride) by Mycobacterium aurum strain LI proceeded by initial formation of an epoxide mediated by an alkene monooxygenase (Hartmans and de Bout 1992). This reaction has also been demonstrated to occur with Methylosinus trichosporium, even though subsequent reactions were purely chemical (Castro et al. 1992b). 

Danko AS, CA Saski, JP Tomkins, DL Freedman (2006) Involvement of coenzyme M during aerobic degradation of vinyl chloride and ethene by Pseudomonas putida strain AJ and Ochrobactrum sp. stain TD. Appl Environ Microbiol 72 3756-3758. 

During the aerobic degradation of chloroethene (vinyl chloride [VC]) by strains of Mycobacteria and Nocardioides, enrichment factors (e) lay within the range -8.2 0.1 to... 

Chartrand MMG, A Waller, TE Mattes, M Eisner, G Lacrampe-Couloume, JM Gossett, EA Edwards, BS Lollar (2005) Carbon isotope fractionation during aerobic vinyl chloride degradation. Environ Sci Technol 39 1064-1070. 

Groundwater. Under aerobic conditions, >99% vinyl chloride degraded in shallow ground-water after 108 d and 65% was completely mineralized (Davis and Carpenter, 1990). 

Trichloroethane was degraded by a dominant aerobic pathway to chloroacetate and glyoxylate, and simultaneously by a minor reductive reaction which must also involve an elimination reaction with the formation of vinyl chloride (Figure 6.70) (Castro and Belser 1990). 

From an environmental point of view, it therefore appears that the complete degradation of chlorinated alkenes and alkanes will often require the operation of both anaerobic and aerobic steps for example, partial or complete dehalogenation may occur under anaerobic conditions, and aerobic degradation of the partially dechlorinated metabolites such as dichlo-romethane (La Roche and Leisinger 1991) and vinyl chloride (Castro et al. 1992a,b Hartmans and de Bont 1992) may then subsequently take place. The combination of the two activities in a single strain has been exploited in the genetically constructed strain of P. putida and has been discussed above. 

BIOLOGICAL PROPERTIES T.O.C. 500 ppm Koc 150 under anaerobic conditions, reductive dechlorination to vinyl chloride occurs under simulated anaerobic landfill conditions, degradation occurred in 1-3 weeks detection in water is by EPA Method 601 inert gas purge followed by gas chromatography with halide specific detection, and by EPA Method 624 gas chromatography plus mass spectrometry aerobic half-life 4 weeks-6 months anaerobic half-life 81 days-173 days... 

Tiehm A, Schmidt KR, Pfeiffer B, Heidinger M, Ertls S. (2008). Growth kinetics and stable carbon isotope fractionation during aerobic degradation of cis-l,2-dichloroethene and vinyl chloride. Water Research 42 2431-2438. 

Although vinyl chloride is carcinogenic in man, specific mycobacteria have been isolated, that are capable of aerobic growth on vinyl diloride as a sole source of carbon and energy. The reason, why these mycobacteria have (developed) the capacity to degrade this truly xenobiotic compound, remains unknown. 

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