title: Inhibition of pure cultures of methanogens by benzene ring compounds.
abstract: The inhibition of methane production by Methanosaeta concilii GP6, Methanospirillum hungatei GP1, Methanobacterium espanolae GP9, and Methanobacterium bryantii M.o.H. during short-term (6-h) exposure to eight benzene ring compounds was studied. The concentration that caused 50% inhibition of the methane production rate (IC50) was dependent on the species and the toxicant. Pentachlorophenol was the most toxic of the tested compounds, with an IC50 of less than 8 mg/liter for all species except M. hungatei. Abietic acid was the next most toxic compound for all the species, with an IC50 in the range of 21.4 to 203 mg/liter. Sodium benzoate was generally the least toxic, with an IC50 in the range of 1,225 to 32,400 mg/liter. 3-Chlorobenzoate was substantially more toxic (IC50, 450 to 1,460 mg/liter) than benzoate. The inhibition by benzene, phenol, vanillic acid, and toluene was intermediate to that of pentachlorophenol and benzoate. Long-term incubation (days) studies to determine effect on growth indicated that all eight compounds were usually much more toxic than predicted from the short-term data. In these latter studies, there was generally a good correlation in the observed inhibition as determined from growth and methane production.
authors.affiliation: Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario.
authors.forename: G B
authors.initials: GB
authors.lastname: Patel
authors.forename: B J
authors.initials: BJ
authors.lastname: Agnew
authors.forename: C J
authors.initials: CJ
authors.lastname: Dicaire
mesh_terms: D045784:Abietanes; D001554:Benzene / Q000633:toxicity*; D001565:Benzoates / Q000633:toxicity; D019817:Benzoic Acid; D004224:Diterpenes / Q000633:toxicity; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000009:adverse effects; D008697:Methane / Q000378:metabolism; D017014:Methanobacterium / Q000187:drug effects / Q000254:growth & development* / Q000302:isolation & purification; D010616:Phenanthrenes; D010622:Phencyclidine / Q000633:toxicity; D019800:Phenol; D010636:Phenols / Q000633:toxicity; D014050:Toluene / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D045784:Abietanes; D001565:Benzoates; D004224:Diterpenes; D007220:Industrial Waste; D010616:Phenanthrenes; D010636:Phenols; D014874:Water Pollutants, Chemical; D019800:Phenol; D014050:Toluene; D019817:Benzoic Acid; D010622:Phencyclidine; D001554:Benzene; D008697:Methane; C023710:abietic acid