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Abstract

A mixed microbial community, specially designed to degrade a wide range of substituted aromatic compounds, was examined for its ability to degrade mono-chlorophenols as sole carbon source in aerobic batch cultures. The mixed culture degraded 2-, 3-, and 4-chlorophenol (1.56 mM) via a meta- cleavage pathway. During the degradation of 2- and 3-chlorophenol by the mixed culture, 3-chlorocatechol production was observed. Further metabolism was toxic to cells as it led to inactivation of the catechol 2,3-dioxygenase enzyme upon meta- cleavage of 3-chlorocatechol resulting in incomplete degradation. Inactivation of the meta- cleavage enzyme led to an accumulation of brown coloured polymers, which interfered with the measurement of cell growth using optical density. Degradation of 4-chlorophenol by the mixed culture led to an accumulation of 5-chloro-2-hydroxymuconic semialdehyde, the meta- cleavage product of 4-chlorocatechol. The accumulation of this compound did not interfere with the measurement of cell growth using optical density. 5-chloro-2-hydroxymuconic semialdehyde was further metabolized by the mixed culture with a stoichiometric release of chloride, indicating complete degradation of 4-chlorophenol by the mixed culture via a meta- cleavage pathway.

Biodegradation of Phenol and Phenolic Derivatives by a Mixture of Immobilized Cells ofAspergillus AwamoriandTrichosporon Cutaneum

“…other authors report that some microorganisms prefer to biodegrade chlorine derivatives in meta-position to the derivatives in para-and ortho-position (14,16).…”

Adsorption of phenolic compounds on low-cost adsorbents: A review

“…Recent literature on the methods of removal of phenol and their compounds from wastewater focuses on adsorption and microbial biodegradation process [61][62][63][64]. Certain species like Pseudomonas sp.…”

Methanization and mineralization of 2-chlorophenol by anaerobic digestion

“…2CP elimination has not been achieved (Farrell & Bridge 1999). Under anaerobic conditions, particularly in methanogenesis, chlorophenols are eliminated by means of reductive dechlorination followed by aromatic ring cleavage and their final conversion to CH 4 and CO 2 (Basu et al 1996;Becker et al 1999).…”