Development of bacterial cultures which can metabolize structural analogs of dioxin

摘要

AbstractWidely present in the environment, the highly‐toxic compound 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) has been found to resist microbial biodegradation. To develop an anaerobic biodegradation approach for soils and sediments contaminated with TCDD, methanogenic and denitrifying cultures were established on a variety of chloroaromatic substrates, including 2‐chlorophenol, 3‐chlorophenol, 4‐chlorophenol, 2,3‐dichlorophenol, 3,4‐dichlorophenol, 4,5‐dichlorocatechol and catechol, using an inoculum from Newtown Creek (New York, NY). Dehalogenation was observed, with monochlorophenols producing phenol and dichlorophenols producing monochlorinated phenols and phenol. Based on gas production, the chlorinated catechol did not appear to undergo biodegradation under any condition, while catechol was degraded under methanogenic conditions. Select cultures amended with a mixture of chloroaromatics and n‐butanol, a solubilizing agent, exhibited depressed gas production under both anaerobic conditions. Biodegradation of TCDD adsorbed onto particles of gallium oxide is under investigation with an amalgamation of the active single‐substrat