高通量测序分析玉米秸秆与牛粪联合发酵阶段微生物多样性变化

High-throughput sequencing analysis of microbial diversity in the combined fermentation stages of cow dung and corn straw

研究比较不同配比微生物菌剂添加对牛粪-玉米秸秆联合沼气发酵的影响,并采用高通量测序技术对添加了最佳菌剂的沼气发酵液中微生物多样性进行分析。结果表明,最佳玉米秸秆-牛粪发酵条件:微生物菌剂配比为蜡样芽孢杆菌、荧光假单胞菌、枯草芽孢杆菌、松嫩假单胞菌(质量比3∶2∶3∶2),在此条件下最高沼气产率和甲烷产率分别达到了72和39 m L/g VS,最高累积产沼气产率和甲烷产率分别达到了778和532 m L/g VS;高通量测序结果表明,细菌中的拟杆菌门(Bacteroidetes)的数量最为丰富,是最主要的优势类群,在沼气发酵过程中的相对丰度变化趋势为增加,由发酵初期33. 8%增加到发酵末期的43. 6%;真菌中子囊菌门(Ascomycota)的数量最为丰富,是最主要的优势类群,沼气发酵过程中相对丰度变化趋势为先增加后降低,由发酵初期65. 7%增加到发酵中期的84. 7%,又降到发酵末期的66. 8%。

Effects of different proportions of microbial agents on the fermentation of cow dung-corn straw combined with biogas fermentation were compared,the high-throughput sequencing technology was used to analyze the microbial diversity in the biogas fermentation broth with the best bacteria.The results showed that the optimal condition to ferment corn straw and cow dung was as follows:microbial agents were Bacillus cereus,Pseudomonas formosensis,Bacillus subtilis,Pseudomonas songnenensis(mass ratio 3∶2∶3∶2).Under these conditions,the highest biogas and methane yield reached 72 mL/g VS and 39 mL/g VS while the highest cumulative biogas and methane yield reached 778 mL/g VS and 532 mL/g VS,respectively.The high-throughput sequencing results showed that Bacteroidetes were the most abundant bacteria and was the most important group of the dominant bacterial species.The relative abundance trend in the biogas fermentation process increased from 33.8%during the early stage of fermentation to 43.6%at the end stage of fermentation.Ascomycota was the most abundant among the fungi.The main dominant group in the biogas fermentation process first increased and then decreased,went from 65.7%during the initial fermentation stages to 84.7%in the middle of the fermentation process and dropped to 66.8%at the end of the fermentation process.The research on combined fermentation of cow dung and corn straw provides a theoretical basis for preparing a biogas agent.