title: Nitrate-reducing bacteria in Kuwait domestic sewage.
abstract: Domestic sewage in Kuwait is mainly treated by an activated-sludge process, where different effluents and sludges are separated. Nitrate reduction in the raw sewage, effluent-1 and effluent-2 were studied. Various enrichments of these sewage samples were effected using 0.2 mg/ml of nitrogen as potassium nitrate and/or 0.5% carbon as glucose. Addition of 0.2 mg/ml nitrate-nitrogen enhanced more ammonia production (117.6 micrograms/ml) in comparison with other enrichments to sewage samples. Nitrate-reducing bacteria were also at a maximum with nitrate enriched sewage samples, especially with effluent-1 (109 X 10(6)/ml). Escherichia coli and Klebsiella pneumoniae were the only two nitrate-reducing bacteria found in all sewage samples tested. Nitrite was unstable during the 7 days incubation period under anaerobic conditions which suggests that nitrates are reduced to ammonia.
mesh_terms: D000693:Anaerobiosis; D004926:Escherichia coli / Q000145:classification / Q000254:growth & development / Q000378:metabolism*; D007711:Klebsiella pneumoniae / Q000145:classification / Q000254:growth & development / Q000378:metabolism*; D007730:Kuwait; D009566:Nitrates / Q000378:metabolism*; D010084:Oxidation-Reduction; D012722:Sewage
chemical_list: D009566:Nitrates; D012722:Sewage