Establish And Research On Composite Of Methanogenic Microbial System

Anaerobic biodegradation is an extremely complex process,all kind of microbial activity are not only interacted, interdependent, but also mutually restricted, which is a complex and orderly system. Fully understand the various micro-organisms'role and influence in the biogas fermentation. Establish a stable and higher efficient composite of methanogenic microbial system, which has significance for increasing biogas production rate, shortening the duration of fermentation start-up, additionally offered a theoretical support for development of biogas fermentation bacterium agents and the realization of biogas fermentation from the natural fermentation to the controllabal fermentation.The research achievements:(1)Using Hungate Anaerobic Technique, 6 strains of methanogenic archaea were isolated from Mt. Ailao in Yunnan Province of China, the Daguan River in Kunming and the other habitats of anaerobic digesters, among which 8-1 is the belongings of Methanobacterium. Sequence analysis of the 16S rRNA genes of strain 8-1 and Methanobacterium subterraneum strain A8p (= DSM 11074T) revealed similarities of 99%. However, the morphological and some physiological characteristics differ from the mode strains, therefore we did further study and published a paper. Another 5 strains ascribed M.formicicum. (2)By enrichment and domestication samples collected from different habitats, we obtained a series of composite of methanogenic microbial system. Additionally grouped them with different ways; added stimulating factors. Eventually we got 7 composite of methanogenic microbial systems with much gas production and stability of pH. We analyzed them with Real-time quantitative PCR and DGGE techniques. Composite system C1, C2, C3,C4,C5 cultured under 35℃for 19 days, the methane content can reach over 50%, Composite system C1 gas production is close to 60% at the 27th day. Low temperature Composite system C6 and C7, under cultivation at 15℃, methane content reach up to 20% at the 19th day; biogas production reach by 25% at the 27th day; 10% higher compared to the control group.