Long-term aerobic cometabolism of a chlorinated solvent mixture by vinyl chloride-, methane- and propane-utilizing biomasses

Aerobic co‐metabolism of 1,1,2,2‐tetrachloroethane by Rhodococcus aetherivorans TPA grown on propane: kinetic study and bioreactor configuration analysis

“…Although CAH biodegradation has been extensively studied both in terms of metabolic pathways and related microorganisms, a very limited number of studies on the biodegradation of chloroethanes, and particularly on TeCA, has been reported . Further, TeCA bioremediation strategies have been mainly evaluated under anaerobic conditions, while it has long been considered non‐biodegradable under aerobic conditions . Complete anaerobic biodegradation and detoxification of TeCA was described with consortia containing multiple dehalorespiring microorganisms whereas pure strains were reported to be able to degrade TeCA incompletely .…”

“…Complete anaerobic biodegradation and detoxification of TeCA was described with consortia containing multiple dehalorespiring microorganisms whereas pure strains were reported to be able to degrade TeCA incompletely . On the other hand, in recent years a limited number of studies demonstrated the possibility to biodegrade TeCA via aerobic co‐metabolism using mixed cultures . Further, some studies have characterized both aerobic and anaerobic microbial communities able to degrade TeCA for bioaugmentation purposes in the light of a bioremediation strategy …”

“…Methane, toluene, phenol, ammonia, propane and butane have been effectively utilized as growth substrates for bacterial CAH aerobic co‐metabolism. In particular, propane‐utilizers have demonstrated the ability to oxidize various CAHs such as vinyl chloride, 1,1,2‐trichloroethane, chloroform, trichloroethylene . Indeed, it was shown that propane induces the synthesis of a monooxygenase that is responsible for one or more CAHs transformation due to its relaxed substrate range .…”

Removal of mixture ofcis-1,2-dichloroethylene/trichloroethylene/benzene, toluene, ethylbenzene, and xylenes from contaminated soil byPseudomonas plecoglossicida

“…Under anaerobic conditions, TCE can be biotransformed through reductive dechlorination, mainly resulting in such toxic metabolites as cis ‐1,2‐dichloroethylene ( cis ‐DCE) and vinyl chloride (VC), and the anaerobic biodegradation process is usually considered requiring more time to complete . Under aerobic conditions, on the other hand, less chlorinated ethenes can be cometabolized and completely mineralized by the microbial oxygenases induced during growth on such primary substrates as toluene, ortho ‐xylene, methane, phenol, propane, isoprene, and ammonia . As both cis ‐DCE and VC as possible intermediate products from the anaerobic biodegradation process are among priority pollutants, it is critical to establish an effective aerobic treatment strategy which does not generate toxic intermediates, and attention has been paid to the aerobic biodegradation of TCE and its metabolites, especially cis ‐DCE …”

Evaluation of Hydrogen/Oxygen Release Compounds for the Remediation of VOCs

“…Cometabolic degradative processes usually involve Chlorinated Aliphatic Hydrocarbons (CAHs), Polychlorobiphenils (PCB) and pesticides. Aerobic cometabolism is effective in medium/low CAHs degradation (Frascari et al, 2006;, although for some of these pollutants (i.e., chlorobenzene, vinyl chloride) microbic species able to play a direct metabolic degradation are available. The aerobic cometabolisms of highly-chlorinated CAHs (i.e., perchloroethylene, PCE, carbon tetrachloride, hexachlorobenzene) is usually inhibited and it happens only with the support of a strong oxidant, therefore the preferential degradation mechanism is anaerobic cometabolism (McCarty, 1993).…”