外加纤维素酶和α-淀粉酶对猪粪厌氧发酵的促进机制  

Stimulation Mechanism of Exogenous Cellulase and α-Amylase on Anaerobic Fermentation of Pig Manure

作　　者：黄婧[1] 肖艳春[1] 陈彪[1] HUANG Jing;XIAO Yanchun;CHEN Biao(Institute of Agricultural Engineering,Fujian Academy of Agricultural Science,Fuzhou 350003,China)

机构地区：[1]福建省农业科学院农业工程技术研究所,福建福州350003

出　　处：《环境科学研究》2020年第8期1964-1972,共9页Research of Environmental Sciences

基　　金：福建省科技厅省属公益类科研项目(No.2014R1015-13,2018R1014-2)。

摘　　要：为有效缩短有机物厌氧发酵限制阶段的反应时间,提高发酵底物的生物产甲烷效率,以猪粪为发酵底物,添加外源纤维素酶和α-淀粉酶,应用一级动力学模型和Gompertz模型拟合厌氧发酵过程.结果表明:适量添加纤维素酶和α-淀粉酶对厌氧发酵系统的水解反应具有积极的促进作用,当两种酶的总添加量为40 mg/g、纤维素酶和α-淀粉酶配比为1∶3时促进作用最为显著,其多糖浓度、TVFAs (乙酸、丙酸、丁酸和戊酸的统称)浓度峰值、累积沼气产气量、甲烷产率(基于猪粪中挥发性固体含量计算)分别为4 494 mg/L、8 666 mg/L、187 688 mL、392.1 mL/g,与CK (对照)组比分别提高了171.0%、23.3%、23.5%、24.3%.相关性分析表明,外源酶的添加对厌氧发酵系统中微生物可利用的C/N具有显著影响,可有效促进TVFAs转化产甲烷,当纤维素酶和α-淀粉酶配比为1∶3时,厌氧发酵过程具有最大反应速率〔32.95 mL/(g·d)〕,与CK组相比水力停留时间(HRT)缩短了2.5 d,生物产甲烷效率提高了24.3%,厌氧发酵过程符合Gompertz模型(R^2=0.999 2).研究显示,纤维素酶和α-淀粉酶对促进猪粪厌氧发酵有协同作用,当α-淀粉酶添加量不超过30 mg/g时,α-淀粉酶添加量与甲烷产率呈正相关;当纤维素酶添加量超过10 mg/g时,纤维系酶添加量与甲烷产率呈负相关.In order to effectively shorten the reaction time of the limiting phase of anaerobic fermentation of organic matters and improve the biomethanation efficiency (BDA) of fermentation substrate,pig manure was used as the fermentation substrate and exogenous cellulase and α-amylase were added. The anaerobic fermentation process was fitted using the first-order kinetic model and the Gompertz model. The results show that under the condition of pH 7. 0 and 35 ℃,adding the appropriate amounts of cellulase and α-amylase had a positive stimulation effect on the hydrolysis reactions of the anaerobic fermentation system. When the total amount of the two enzymes was 40 mg/g and the ratio of cellulase and α-amylase was 1 ∶3,the stimulating effect was most significant. The concentration of soluble polysaccharides,the peak value of total volatile fatty acids (TVFAs),the cumulative biogas production,and the yield of methane which calculation method based on volatile solid content of pig manure,were 4,494 mg/L,8,666 mg/L,187,688 mL,and 392. 1 mL/g,respectively,which were 171. 0%,23. 3%,23. 5% and 24. 3% higher than those of the CK group (the control group),respectively. Our analysis shows that adding exogenous enzymes had a significant effect on the available C/N ratio of microorganisms in the fermentation system,and effectively improved the conversion rate of TVFAs toward methane. In the anaerobic fermentation process,the 1∶3 ratio treatment group had the highest reaction rate (32. 95 mL/ (g·d)),the hydraulic retention time (HRT) was 2. 5 d shorter than that of the CK group,and the BDA increased by 24. 3%. The anaerobic fermentation process was in accordance with the Gompertz model (R^2= 0. 999,2). This study shows that exogenous cellulase and α-amylase had a synergistic effect on the promotion of anaerobic fermentation of pig manure. When the amount of α-amylase did not exceed 30 mg/g,the amount of addition was positively correlated with the methane yield;when the amount of cellulase exceeded 10 mg/g,the amount of ad

关 键 词：猪粪 外源酶 Gompertz模型 生物产甲烷效率 

分 类 号：X713[环境科学与工程—环境工程]