Isolation of High-Efficient Low-Temperature Methanogen and Comparation on Flora in Anaerobic Fermentation Production Biogas

With the Hungate anaerobic techniques, a low-temperature methanogen strain was isolated from sludge in De Qing Alpine region from Tibet, named XZF21. The colony is white, not transparent, Gram-negative, uses formate as the substrate for CH4 formation, the most suitable growth temperature is 23°C, most suitable pH is 7.0 with yeast extract, the shape, physical characteristics and the analysis of 16S rDNA indicated that this bacteria is Methano corpusculum parvum. Methane bacteria and coupled bacteria as inoculum in the fish pond sludge and fresh pig manure, under the strict fermentation temperature (23±1°C) to contrast the biogas production. The result showed: Compared the sludge and pig manure as fermentation medium, increasing the bacterias can largely enhance the methane production. Further more, with the pig manure as fermentation matrix is more advantageous for the methane synthesis than that sludge, and the production of biogas is four times higher than the sludge, the degeneration rate of TS and VS improved 25.20%-32.35%, 6.28%-14.85% respectively.