The Role of Facultative Anaerobic Micro-Organisms in Anaerobic Biodegradation of Chlorophenols

Abstract

Pure cultures of facultative anaerobic bacteria and yeasts were isolated from anaerobic reactors fed synthetic wastewater which contained eight different chlorophenolic compounds. The concentration of facultative anaerobic micro-organisms was followed in the reactor throughout the experimental period, during which the chlorophenol concentrations were increased and many of the chloronated phenols were removed nearly completely. The most common species were Klebsiella spp. and K. Pneumoniae. Some of the common colonies were tentatively identified as Pseudomonas-like organisms and Aeromonas hydrofila. Methanogenic bacteria in the reactor were mainly acetate users. When the total chlorophenol concentration in the feed was increased from zero to 2.4 or 5.3 mg/1, the concentration of Pseudomonas-like organisms increased, as did the concentration of yeasts. Pure and mixed cultures were tested for use of 2,4,6-trichlorophenol (246-TCP) as a sole carbon and energy source under anaerobic conditions. None of the isolates were able to degrade 246-TCP under anaerobic conditions in pure culture. However, mixed cultures containing only P. aeruginosa and K. oxytoca were able to degrade 246-TCP.

Stenotrophomonas acidaminiphila sp. nov., a strictly aerobic bacterium isolated from an upflow anaerobic sludge blanket (UASB) reactor.

“…ecosystems, of aerobic, non-sporulating, Gram-negative, flagellated, chemo-organotrophic proteobacteria that possess a strictly respiratory energy-yielding metabolism (Britz et al, 1994 ;Hakulinen et al, 1985 ;Ng et al, 1994 ;Toerien & Hattingh, 1969). A wide diversity of genera, including Stenotrophomonas, are members of this heterogeneous group with versatile metabolisms.…”

Methods for Separation, Recycling and Reuse of Biodegradation Products

“…Chlorinated phenols are common and encountered even in relatively pristine environments [82,83]. These compounds are formed during the bleaching of pulp with chlorine [82][83][84]. As the pulp accounts only for about 40-45% of the original weight of the wood, these effluents are heavily loaded with organics [85].…”

Removal of aqueous phenol and phenol derivatives by immobilized potato polyphenol oxidase

“…1 These pollutants are non-biodegradable and are known to have carcinogenic, mutagenic or chronic toxic effects. A few persistent pollutants, including several pesticides, are carried in air and water over several hundred kilometers, affecting the wildlife and general population.…”