Degradation of chlorinated phenols by a pentachlorophenol-degrading bacterium

Abstract

A pentachlorophenol (PCP)-degrading Flavobacterium sp. was tested for its ability to dechlorinate other chlorinated phenols by using resting cells that had been grown in the presence or absence of PCP. Phenols with chlorine atoms at positions 2 and 6 of the phenol ring were dechlorinated completely by PCP-induced cells. Other chlorinated phenols were not significantly mineralized. When PCP was added to a culture growing on L-glutamate, there was a lag period before the start of PCP degradation. When similar cells were treated with chloramphenicol prior to the addition of PCP, they did not degrade added PCP, even after prolonged incubations. Thus, the enzymes necessary for PCP degradation appeared to be inducible. Suspensions of cells grown in the presence of 2,4,6-trichlorophenol or 2,3,5,6-tetrachlorophenol did not show a lag period for mineralization of PCP, 2,4,6-trichlorophenol, or 2,3,5,6-tetrachlorophenol, indicating that one enzyme system probably was induced for the biodegradation of all three compounds. Nondegradable chlorophenols were toxic toward the Flavobacterium sp., probably acting as uncouplers of oxidative phosphorylation.

Degradation of trichlorophenols by Alcaligenes eutrophus JMP134

“…In turn, cells of Fluvobacterium sp. also degrade 2,4,6-trichlorophenol but left 2,4,5trichlorophenol untouched [17]. On the other hand, Nocurdioides simplex E3 and Pseudomonas cepacia ACllOO, able to grow on 2,4,5trichlorophenoxyacetate, also grow on 2,4,5-trichlorophenol [18,19].…”

Microbial breakdown of halogenated aromatic pesticides and related compounds

“…Many of the pentachlorophenol-degrading strains are able to also degrade several tetraand trichlorophenols, but have low activity for mono-and dichlorophenols [43,[46][47][48][49][50][51]. The degradation of pentachlorophenol and other polychlorophenols was shown to be inducible in several of the strains [43,[47][48][49]52,53]. Those isolates for which the initial reactions are known degrade polychlorinated phenols by mechanisms in which the chlorine substituents are removed before cleavage of the aromatic ring.…”

Removal of 2,4,5‐trichlorophenol by bacterial isolates from the secondary sludge of pulp and paper mill

“…Though the present study isolates were able to degrade both PCP [15,22,23] and 2,4,5-TCP, their degradation abilities varied depending on the type of chlorophenol. Steiert et al [24] suggested that the chlorine atom substitution patterns on the phenol ring appeared to be the important regulators of dechlorination of chlorophenols and mineralization by Flavobacterium sp. Contrary to this Yang et al [2] reported that the ability of S. chlorophenolica cells to degrade various chlorophenols was not related to the chlorine ring substitution patterns of specific compounds; rather it may be due to the metabolic pathway of this strain.…”