Reductive dechlorination of chlorophenols by a pentachlorophenol- acclimated methanogenic consortium.
Anaerobic digester sludge fed 5,300 mg of acetate per liter, 3.4 microM pentachlorophenol, and nutrients for 10 days biotransformed pentachlorophenol by sequential ortho dechlorinations to produce 2,3,4,5-tetrachlorophenol and 3,4,5-trichlorophenol. Upon acclimation to 3.4 microM pentachlorophenol for 6 months, the methanogenic consortium removed chlorines from the ortho, meta, and para positions of pentachlorophenol and its reductive dechlorination products. Pentachlorophenol was degraded to produce 2,3,4,5-tetrachlorophenol, 2,3,4,6-tetrachlorophenol, and 2,3,5,6-tetrachlorophenol. Dechlorination of 2,3,4,5-tetrachlorophenol produced 3,4,5-trichlorophenol, which was subsequently degraded to produce 3,4-dichlorophenol and 3,5-dichlorophenol. 2,3,4,6-Tetrachlorophenol was dechlorinated at the ortho and meta positions to produce 2,4,6-trichlorophenol and 2,4,5-trichlorophenol. 2,3,5,6-Tetrachlorophenol yielded 2,3,5-trichlorophenol, followed by production of 3,5-dichlorophenol. 2,4,6-Trichlorophenol was degraded to form 2,4-dichlorophenol, and 2,4,5-trichlorophenol was dechlorinated at two positions to form 2,4-dichlorophenol and 3,4-dichlorophenol. Of the three dichlorophenols produced (2,4-dichlorophenol, 3,4-dichlorophenol, and 3,5-dichlorophenol), only 2,4-dichlorophenol was degraded significantly within 3 weeks, to produce 4-chlorophenol.
Nicholson
D K
DK
Department of Civil Engineering, Oregon State University, Corvallis 97331-2302.
Woods
S L
SL
Istok
J D
JD
Peek
D C
DC
D000222:Adaptation, Physiological; D001673:Biodegradation, Environmental; D001711:Biotransformation; D002733:Chlorophenols / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics; D004785:Environmental Pollutants / Q000378:metabolism; D019605:Euryarchaeota / Q000378:metabolism*; D010084:Oxidation-Reduction; D010416:Pentachlorophenol / Q000378:metabolism / Q000493:pharmacokinetics
D002733:Chlorophenols; D004785:Environmental Pollutants; D010416:Pentachlorophenol