Dechlorination of pentachlorophenol by membrane bound enzymes of Rhodococcus chlorophenolicus PCP-I.
Dechlorination (para-hydroxylation) of pentachlorophenol (PCP) and tetrachloro-para-hydroquinone (TeCH) and O-methylation of TeCH were demonstrated in cell extracts of Rhodococcus chlorophenolicus PCP-I. PCP para-hydroxylating activity was membrane bound, whereas TeCH dechlorinating enzyme was soluble. The PCP para-hydroxylating enzyme was solubilized by Triton X-100 and the requirement for both FAD and NADPH was shown. The dechlorinating activities were inducible in contrast to the constitutive TeCH O-methylating activity. The PCP para-hydroxylation was inhibited by its product TeCH, by anoxic conditions, and by different inhibitors of P450. Participation of this cytochrome in the PCP hydroxylation was confirmed by the appearance of a carbon monoxide dependent peak of absorbance at 457 nm in the membrane fraction prepared from PCP degrading cells.
University of Helsinki, Department of General Microbiology, Finland.
J S
JS
Uotila
M S
MS
Salkinoja-Salonen
J H
JH
Apajalahti
D001673:Biodegradation, Environmental; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D006873:Hydroquinones / Q000378:metabolism; D006900:Hydroxylation; D008566:Membranes / Q000201:enzymology; D010416:Pentachlorophenol / Q000378:metabolism*; D012240:Rhodococcus / Q000378:metabolism*
D006873:Hydroquinones; C044578:2,3,5,6-tetrachlorohydroquinone; D003577:Cytochrome P-450 Enzyme System; D010416:Pentachlorophenol