Preliminary Study On High-temperature Biogas Fermentation With Edible Fungi Residue And Isolation Of Methanogenic Bacteria

With the rapid development of biogas business and the industrialization of edible fungi production in recent years, Heilongjiang, as energy-consuming and agricultural province, has built a large number of household biogas digesters and edible fungi base. So the studies, which combine the reuse of edible fungi residue and biogas production, have great significance. Now the researches about biogas fermentation with edible fungi residue are rarely. The test contained three aspects: study on the optimum fermentation conditions for biogas fermentation with edible fungi residue; study on biogas fermentation with edible fungi residue and cow dung; isolation of methanogen in the process of biogas fermentation. The aim of our studies will provide a new direction for biogas fermentation and the treatment of edible fungi residue. The results are as follows:1. Edible fungi residue can be used as favorable material of biogas fermentation. Using biogas slurry to replace water completely could quickly inatiate biogas fermentation, and make if come up to the peak of biogas production. Under 53℃, the optimum fermentation TS% is 10%. The potential production of biogas was 367.5mL/gTS. Adding urea could evidently increase biogas yield and the content of CH4, and the optimum additive amount was 0.25~0.3%.2. Regulation of the proportion of edible fungi residue and cow dung could change material structure, improve conversion rate of materials, and increase biogas production. Under the same fermentation conditions, following the change of the kind of edible fungi residue, the optimum proportion would change. When the proportion of agaric to cow dung was 40:60, or the proportion of hericium residue to cow dung was 50:50, the biogas yield came up to the maximum.3. We isolated a strain of methanogen from biogas slurry of edible fungi residue. The strain is coccoid, single or doubling appeared, G—, non-motile, and didn't form bud-spore. The colony was circular, translucent, smooth, and emits cyancolor fluorescence under the ultraviolet fluorescence microscope. The optimum temperature of the strain is 45~55℃, and the optimum growth pH is 6.6~7.5.The strain can use formate, but not methanol, propul et al. The optimum Na+ concentration is less than 0.2mol/L. The strain has penicillin tolerance and tetracycline tolerance.