Turnover of propionate in methanogenic paddy soil

• Published in: FEMS microbiology ecology 1997-06, Vol.23 (2), p.107-117
• Main Authors: Krylova, N.I. (Max-Planck-Institut fuer Terrestrische Mikrobiologie, Marburg (Germany).), Janssen, P.H, Conrad, R
• Format: Article
• Language: English
• Subjects: Acetate; Acetic acid; AIR POLLUTION; Bacteria; Bicarbonates; Carbon dioxide; Chloroform; Crop production; Ecology; Free energy; Gibbs free energy; Hydrogen; Iron; Lag phase; METANO; METHANE; Methanogenesis; Methanogenic bacteria; Microbiology; Molybdate; ORYZA SATIVA; PADDY SOIL; PAILLE DE RIZ; PAJA DE ARROZ; POLLUTION ATMOSPHERIQUE; POLUCION DEL AIRE; PROPIONATE; Propionate degradation pathway; PROPIONATES; PROPIONATOS; Propionic acid; Rice fields; RICE STRAW; Slurries; Soil amendment; Soils; SOL DE RIZIERE; Straw; SUELO DE ARROZALES; Sulfates; Syntrophy
• ISSN: 0168-6496; 1574-6941
• DOI: 10.1111/j.1574-6941.1997.tb00395.x

Abstract Samples from planted Italian paddy soil exhibited most probable numbers (MPN) of about 107 anaerobic propionate utilizers. In anoxic soil slurries that were either unamended or amended with rice straw production of CH4 was measured together with concentrations of H2, acetate and propionate. After a lag phase, during which ferric iron was depleted, CH4 was produced at a constant rate which was slightly higher in the straw-amended than in the unamended soil. Propionate concentrations were relatively low at about 5–15 μM. However, in the straw-amended soil propionate transiently accumulated to about 35 μM just after onset of methanogenesis. During the period of propionate accumulation H2 partial pressures were elevated and the Gibbs free energy (ΔG) of propionate consumption to acetate, bicarbonate and H2 was endergonic or higher than −3 kJ mol−1 propionate. Propionate concentrations decreased again when the ΔG decreased to more negative values. In unamended paddy soil, propionate did not accumulate transiently and ΔG was always