Contribution of quinone-reducing microorganisms to the anaerobic biodegradation of organic compounds under different redox conditions

• Published in: Biodegradation (Dordrecht) Vol. 19; no. 2; pp. 235 - 246
• Main Authors: Cervantes, Francisco J, Gutiérrez, Claudia H, López, Kitzia Y, Estrada-Alvarado, María Isabel, Meza-Escalante, Edna R, Texier, Anne-Claire, Cuervo, Flor, Gómez, Jorge
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01-04-2008; Springer Netherlands; Springer; Springer Nature B.V
• Subjects: Anaerobic biodegradation; Aquatic Pollution; Bacteria, Anaerobic - metabolism; Benzoquinones - metabolism; Biodegradation; Biodegradation of pollutants; Biodegradation, Environmental; Biological and medical sciences; Biomedical and Life Sciences; Biotechnology; Competition; Denitrification; Ecology; Environment and pollution; Fundamental and applied biological sciences. Psychology; Geochemistry; Global climate; Greenhouse effect; Humus reduction; Industrial applications and implications. Economical aspects; Industrial Waste; Life Sciences; Methane; methane production; Methanogenesis; Microbiology; Microorganisms; Nitrates; Organic Chemicals - metabolism; Organic compounds; Original Paper; Oxidation; Oxidation-Reduction; Phenols; Sewage; Sludge; Soil Science & Conservation; Sulfate reduction; Sulfates; Terrestrial Pollution; Waste Disposal, Fluid; Waste Management/Waste Technology; Waste Water Technology; Water Management; Water Pollution Control; Competition; Sulfate reduction; Denitrification; Humus reduction; Methanogenesis; Biodegradation; Sulfatoreduction; Quinone; Reduction; Humus; Anaerobe; Microorganism; Organic compounds
• ISSN: 0923-9820; 1572-9729
• DOI: 10.1007/s10532-007-9130-x

The capacity of two anaerobic consortia to oxidize different organic compounds, including acetate, propionate, lactate, phenol and p-cresol, in the presence of nitrate, sulfate and the humic model compound, anthraquinone-2,6-disulfonate (AQDS) as terminal electron acceptors, was evaluated. Denitrification showed the highest respiratory rates in both consortia studied and occurred exclusively during the first hours of incubation for most organic substrates degraded. Reduction of AQDS and sulfate generally started after complete denitrification, or even occurred at the same time during the biodegradation of p-cresol, in anaerobic sludge incubations; whereas methanogenesis did not significantly occur during the reduction of nitrate, sulfate, and AQDS. AQDS reduction was the preferred respiratory pathway over sulfate reduction and methanogenesis during the anaerobic oxidation of most organic substrates by the anaerobic sludge studied. In contrast, sulfate reduction out-competed AQDS reduction during incubations performed with anaerobic wetland sediment, which did not achieve any methanogenic activity. Propionate was a poor electron donor to achieve AQDS reduction; however, denitrifying and sulfate-reducing activities carried out by both consortia promoted the reduction of AQDS via acetate accumulated from propionate oxidation. Our results suggest that microbial reduction of humic substances (HS) may play an important role during the anaerobic oxidation of organic pollutants in anaerobic environments despite the presence of alternative electron acceptors, such as sulfate and nitrate. Methane inhibition, imposed by the inclusion of AQDS as terminal electron acceptor, suggests that microbial reduction of HS may also have important implications on the global climate preservation, considering the green-house effects of methane.