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| 柳枝稷与苜蓿的共发酵对厌氧发酵体系产气效率及微生物群落的影响 |
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孙宇1,刘燕2,3,陈啸天2,于海茹4,袁旭峰2,赵洪颜1*,崔宗均2*
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| (1.延边大学 农学院, 吉林 延吉133002;2.中国农业大学 农学院, 北京100193;3.四川硕盟农业科技有限公司, 成都 610093;4.延边州特色产业中心, 吉林 延吉 133002) |
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| 摘要: |
| 为了探究远离畜牧区厌氧发酵的原料碳氮营养合理配比问题。以柳枝稷与紫花苜蓿为试验材料，进行两者5种相同含固率、不同配比的批次发酵试验，柳枝稷和苜蓿不同TS配比如下:A组为0∶4；B组为1∶3；C组为1∶1；D组为3∶1；E组为4∶0。通过对产气量、pH、挥发性脂肪酸以及微生物群落变化的分析，探究发酵体系营养平衡及产甲烷特性。结果表明:柳枝稷与苜蓿为原料的5个组产气趋势均为三峰曲线，发酵1 d后出现第一峰，5~8 d出现第二峰，9~12 d出现第三峰，随后下降至很低点；试验中苜蓿含量较多的A、B、C组产气高峰出现的早，在第9 d产气基本结束，随着柳枝稷含量的增加产气峰往后延迟，D组在12 d产气结束，纯柳枝稷的E组在15 d产气结束，这时5个组分别完成总产气量的95.6%、93.3%、93.8%、94.4%、97.2%；累积产气量随柳枝稷含量的增加而增加，5个组甲烷产量分别为291.7、287.7、320.3、357.4和362.2 mL/g VS；随柳枝稷含量的提高，发酵体系pH的下降和挥发性酸的积累明显，纯柳枝稷的发酵体虽然产气多，但发酵体系稳定性下降，其中D组可以明显提高厌氧发酵体系的碳氮营养平衡和缓冲能力，提高发酵体系的稳定性；对5个组的微生物群落进行分析，结果表明:细菌主要的优势菌群为厚壁菌门和拟杆菌门，古菌的优势菌群为甲烷鬃毛菌和甲烷杆菌。综上，柳枝稷与苜蓿按原料含固率3∶1混合进行厌氧发酵，有利于厌氧发酵水解菌群和产甲烷菌群的大量增殖及产甲烷反应。 |
| 关键词: 柳枝稷 苜蓿 厌氧共发酵 碳氮平衡 产气效率 边际土地 |
| DOI：10.11841/j.issn.1007-4333.2022.12.17 |
| 投稿时间：2022-03-10 |
| 基金项目:国家公益性行业(农业)科研专项(201503137)；吉林省科技厅重点研发项目(20200402040NC)；吉林省自然科学基金项目(YDZJ202201ZYTS578) |
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| Effects of co-fermentation of switchgrass and alfalfa on the gas production efficiency and microbial community of anaerobic co-fermentation system |
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SUN Yu1,LIU Yan2,3,CHEN Xiaotian2,YU Hairu4,YUAN Xufeng2,ZHAO Hongyan1*,CUI Zongjun2*
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| (1.College of Agriculture, Yanbian University, Yanji 133002, China;2.College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China;3.Sichuan Shuomeng Agricultural Science and Technology Co., Ltd., Chengdu 610093, China;4.Characteristic industry center of Yanbian Prefecture, Yanji 133002, China) |
| Abstract: |
| In order to explore the optimal ratio of carbon and nitrogen in anaerobic fermentation of raw materials far away from animal husbandry areas, this study used switchgrass and alfalfa as experimental materials, and carried out batch fermentation experiments with the same solid content and different five ratio of switchgrass and alfalfa. Different TS ratios of switchgrass and alfalfa were as follows: A was 0∶4; B was 1∶3; C was 1∶1; D was 3∶1; E was 4∶0. Through the analysis of gas production, pH, volatile fatty acids and microbial community changes, the nutrient balance and methane production characteristics of fermentation system were investigated. The results showed that: The gas production of five proportions digester had a three-peak curve, the first peak appeared after day 1, the second peak appeared after 5-8 days, the third peak appeared after 9-12 days, and then decreased. The gas production peak of A, B and C with more alfalfa appeared earlier and basically ended on the 9th day. With the increase of switchgrass proportion, the gas production peak was delayed later. The group D ended on the 12th day, and E with all switchgrass ended on the 15th day. During this period, the 5 different ratios completed 95. 6%, 93. 3%, 93. 8%, 94. 4%, 97. 2% of the total gas production, respectively. With the increase of switchgrass proportion, the cumulative gas production of five ratios increased respectively by 291. 7, 287. 7, 320. 3, 357. 4 and 362. 2 mL/g VS, and pH decreased and volatile fatty acid accumulated obviously. Although the gas production of pure switchgrass was highest, the stability of digester was decreased. The group D of substrate significantly improved the balance of carbon and nitrogen and buffering capacity of digester, thus improved the stability of fermentation system. The microbial community of the 5 groups was analyzed and compared. The results showed that the dominant bacteria were Firmicutes and Bacteroidetes, and the dominant archaea were Methanosaetaceae(Mst)and Methanobacteriales(MBT). In conclusion, The mixture of switchgrass and alfalfa with solid content 3∶1 is beneficial to the proliferation of hydrolytic bacteria and methanogenic bacteria and methanogenic reaction. |
| Key words: switchgrass alfalfa anaerobic co-fermentation carbon nitrogen horizontal gas production efficiency marginal land |
