Microbial Dehalogenation of Haloalkanes Mediated by Oxygenase or Halidohydrolase

Microorganisms utilizing 1-chlorobutane as a sole carbon and energy source for growth could release halogens under anaerobic conditions, while microorganisms which could utilize 1,9-dichlorononane released the halogens only under aerobic conditions. A 1-chlorobutane-utilizing bacterium, strain ml5-3, converted 1-chlorobutane to butyric acid and 1,3-dichloropropane to 3-chloropropionic acid under aerobic conditions and 1-chlorobutane to butanol under anaerobic conditions. In the latter case, the participation of halidohydrolase was suggested. Methane-utilizing bacteria catalyzed the removal of halogens from the terminal positions of short chained chlorinated hydrocarbons. Methane-utilizing bacteria dehalogenated 1,2-dich-loroethane to ¹⁸O-incorporated 2-chloroacetic acid in the presence of ¹⁸0₂ gas. All of the seven bacterial strains used in this study dehalogenated 3-chlorinated aliphatic acids, but only one strain out of seven could dehalogenate 2-chlorinated aliphatic acids.