Methanogenic archaeon as biogas producer in psychrophilic conditions

The aim of the study was to determine the effectiveness of biogas production as a result of degradation of various organic compounds by psychrophilic methanogenic archaeon Methanococcoides burtonii. Depending on experimental variant, fermented glucose, whey, bovine liquid manure and sewage sludge were used as substrates. The effectiveness of methane fermentation was measured using 500 mL respirometers incubated at a temperature of 20 °C for 50 days. The highest yield of biogas production was noted in the variant with sewage sludge provided in the quantity that ensured the initial tanks loading at 0.2 g COD/L (133 mL CH4/g CODfed). In this variant, analyses showed also one of the highest concentrations of CH4 in biogas produced (53.4%). The high content of methane and high production yield of this biogas component were also reported for the variants with sewage sludge at the loading of 2.0 g COD/L, with bovine liquid manure at the loading of 5.0 g COD/L and with glucose at the loading of 1.0 g COD/L. In these variants, the content of CH4 in biogas produced reached from 37.6 to 57.1%. Taking into account the quantity of produced biogas and CH4 concentration from various organic substrates during fermentation process in psychrophilic conditions run by M. burtonii strain, the results of this study may be considered promising for the perspective application.