Effect of acclimatized paddy soil microorganisms using swine wastewater on degradation of rice straw

Rice straw (RS) is one of abundant agricultural waste for biogas production in China. However, the low carbon-methane conversion rate limits its wide application due to the low degradation rate of RS during fermentation. This study investigated the effect of acclimatized paddy soil microorganisms using swine wastewater on degradation of RS before anaerobic digestion. The total organic carbon, reducing sugar and NH₄⁺-N content of paddy soil + RS + swine wastewater (PRS) (653.50 mg/L) was higher than that of other groups after 19 days. The carboxymethyl cellulose activity (4.01 IU), cellulose/lignin ratio (5.25) and the degradation rate of lignin (51.96%) in PRS were higher than those of other groups. The Firmicutes (21.02%), Chloroflexi (12.48%), Proteobacteria (20.92%), and Bacteroidetes (25.78%) were the main fermentation phyla in PRS during acclimatization. These results indicated that the acclimatized paddy soil microorganisms using swine wastewater (SW) could degrade RS more efficiently.