稻田土菌群驯化对稻秆两步发酵产甲烷效果的影响

To improve the degradation rate of rice straw and methane yield during anaerobic digestion, this paper aimed to domesticate the paddy soil microorganisms by swine wastewater（high NH₄⁺-N）as nitrogen source, optimize the initial pH value of degraded rice straws and evaluate the methane production of hydrolysates during liquid fermentation. The results showed that the CMCase activity and degradation rate of lignin in mixed group was 4.01 IU and 51.96%, which was higher than other groups. In addition, the total organic carbon（TOC, 653.50 mg·L^-1）and reducing sugar（186.84 mg·L^-1）content in hydrolysate reached highest value. The degradation rate of cellulose, hemicellulose and lignin of rice straw significantly increased with increase of pH value, and the volatile fatty acids（VFAs, 6.76 g·L^-1）and TOC（6.92 g·L^-1）content in rice hydrolysate peaked in day 7 at pH 9.0. After 7 d hydrolysis of rice straw, the liquid-hydrolysate was used for anaerobic digestion, the cumulative CH₄ yield under initial pH 9.0 is maximum value（37.60 mL·mL^-1 hydrolysate）. The above results showed that acclimated paddy soil microorganisms under weak alkaline condition can increase degradation rate of rice straw and methane production by two-step anaerobic digestion of wastewater-rice straw.