Sulfate-reduction in the anaerobic digestion of animal waste.

Abstract

The relationship between sulfate-reduction and the oxidation of various intermediates of anaerobic digestion of animal waste was investigated by incubating cattle waste anaerobically in the presence or absence of sulfate. Propionate oxidation was strongly accelerated by the addition of sulfate, but acetate oxidation was not affected. Lactate, butyrate, and ethanol were oxidized rather rapidly irrespective of the presence of sulfate. Hydrogen gas stimulated both sulfate-reduction and methanogenesis, but it delayed the oxidation of fatty acids. When methanogenesis was inhibited by the addition of chloroform in the presence of sulfate, the sulfate was ordinarily reduced, while the acetate concentration increased. It was concluded that the contribution of acetate as an electron donor for sulfatereduction was very low in cattle waste. Sulfate-reduction in pig waste and a ditch sediment was also investigated for comparison.

Rhizomicrobium palustre gen. nov., sp. nov., a facultatively anaerobic, fermentative stalked bacterium in the class Alphaproteobacteria isolated from rice plant roots

“…Utilization of carbon sources was tested in PY liquid medium with each substrate added at 10 g L 1 (for sugars and sugar alcohols) or 30 mM (organic acids, amino acids and alcohols). Fermentation products (fatty acids, alcohols and H 2 ) were analyzed by gas-chromatography (GC) as described previously (Akasaka et al, 2003a;Satoh et al, 2002;Ueki et al, 1986). Nitrate-reducing activity was determined in PY liquid medium supplemented with 2 g L 1 NaNO 3 using glucose (2 g L 1 ), acetate, lactate, methylamine, methanol or ethanol (20 mM each) as a possible electron donor.…”

Propionicimonas paludicola gen. nov., sp. nov., a novel facultatively anaerobic, Gram-positive, propionate-producing bacterium isolated from plant residue in irrigated rice-field soil

“…Utilization of carbon sources was tested in PY liquid medium with each substrate added at 10 g l 21 (for mono-, di-, tri-and polysaccharides and sugar alcohols) or 30 mM (for alcohols and organic acids). Fermentation products were analysed as described previously (Ueki et al, 1986;Akasaka et al, 2003). Glucose concentrations in the media were measured with a D-glucose kit (Boehringer Mannheim) according to the manufacturer's protocol.…”

Desulfovibrio butyratiphilus sp. nov., a Gram-negative, butyrate-oxidizing, sulfate-reducing bacterium isolated from an anaerobic municipal sewage sludge digester

“…Volatile fatty acids, non-volatile fatty acids, alcohols, gases, sulfate, sulfite, thiosulfate and nitrate were analysed as described by Akasaka et al (2003a), Nakamoto et al (1996) and Ueki et al (1986). The presence of desulfoviridin in cells was determined according to the method of Postgate (1959).…”