Vegetable Waste Promotes Methane Production In Cow Dung And Corn Straw Co-fermentation Systems By Enhancing The Degradation Of Cellulose

Nowadays,too many fossil fuels have been explored,we need to find out attractive replacements for fossil fuels which is beneficial to global environment and human development.Anaerobic digestion is a good way to produce clean energy at low costs and is suitable for large scale production.However,the productivity of anaerobic digestion cannot keep high and stable efficiency because of technology limitation,especially pH and temperature sensitivity.The purpose of this study was to investigate the impact of vegetable wastes on the fermentation process during anaerobic co-digestion.Four experimental groups were set up as follows(55 g): 100% cow dung(C);36% cabbage and 64% cow dung(CC);36% straw and 64% cow dung(SC);and 18% cabbage,18% straw and 64% cow dung(CSC).After seven days fermentation,the maximum methane yield was 134 ml in the CSC group which was 1.81-fold,0.78-fold and 1340-fold higher than that in CC,SC and C groups,respectively.VW treatment in the CSC group enhanced cellulase activitiy and enriched culturable cellulose-degrading bacterial strains.What's more,qRT-PCR data revealed that the expression level of cellulose-utilizing strain,bacillus was enhanced after adding vegetable waste and straw.Furthermore,Miseq sequencing results showed that Proteobacteria,Bacteroidetes,Firmicutes and Actinobacteria represented the dominant phylogenetic groups.Our results suggested that VW treatment elevated cellulose degradation and promoted methane production.