Screening of Efficient Acid-production Composite Microbial System in the Biogas Fermentation of Different Straw

[Objective] The research aimed to screen the efficient composite microbial system which produced the acid in the biogas fermentation of different straw.[Method] The wheat straw and corn straw were the carbon sources,and the cow dropping was the nitrogen source.After the multi-generations training,the acid production situations of different microbial systems when the different straw was the carbon source were studied.Moreover,the distillation was used to measure the content of total volatile fatty acid(VFA).[Result] When the wheat straw was the carbon source,the microbial system from the bovine stomach content had the efficient acid-production ability.When the corn straw and the mixed straw were the carbon sources,the microbial system from the humus soil had the efficient acid-production ability.[Conclusion] The research was favorable to improve the utilization ratio of straw lignin in the acidogenic phase and the gas-production rate of gas-production phase in two-phase biogas production.