Aerobic Microbial Mineralization of Dichloroethene as the Sole Carbon Substrate

Microorganisms indigenous to the bed sediments of a black-water stream utilized 1,2-dichloroethene (1,2-DCE) as a sole carbon substrate for aerobic metabolism. Although no evidence of growth was observed in the minimal-salts culture media used in this study, efficient aerobic microbial mineralization of 1,2-DCE as sole carbon substrate was maintained through three sequential transfers (10⁷ final dilution) of the original environmental innoculum. These results indicate that 1,2-DCE can be utilized as a primary substrate to support microbial metabolism under aerobic conditions. The results of this study have important implications for the natural attenuation of DCE in contaminated environments. Although aerobic cometabolism of DCE is well-established, this process is probably restricted to the fringe of contaminant plumes because readily oxidizable substrates and oxygen rarely co-occur within the core of mature contaminant plumes. However, the fact that microorganisms can also utilize DCE as a sole carbon substrate to support metabolism suggests that DCE can be degraded as a primary substrate in microbial metabolism and that this process may contribute to the natural attenuation of DCE even under circumstances where aerobic cometabolism is not favored.

Reference

• Bradley, P.M., and Chapelle, F.H., 2000,
  Aerobic microbial mineralization of dichloroethene as sole carbon substrate: Environmental Science and Technology, v. 34, no. 1, p. 221-223.

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