Liu Tong, Schnürer Anna, Björkmalm Johanna, Willquist Karin, Kreuger Emma
Department of Molecular Science, Swedish University of Agricultural Science, Uppsala BioCenter, 750 07 Uppsala, Sweden.
RISE, Forskningsbyn Ideon Scheelevägen 27, 223 70 Lund, Sweden.
Microorganisms. 2020 Sep 11;8(9):1394. doi: 10.3390/microorganisms8091394.
The use of straw for biofuel production is encouraged by the European Union. A previous study showed the feasibility of producing biomethane in upflow anaerobic sludge blanket (UASB) reactors using hydrolyzed, steam-pretreated wheat straw, before and after dark fermentation with , and lucerne. This study provides information on overall microbial community development in those UASB processes and changes related to acidification. The bacterial and archaeal community in granular samples was analyzed using high-throughput amplicon sequencing. Anaerobic digestion model no. 1 (ADM1) was used to predict the abundance of microbial functional groups. The sequencing results showed decreased richness and diversity in the microbial community, and decreased relative abundance of bacteria in relation to archaea, after process acidification. Canonical correspondence analysis showed significant negative correlations between the concentration of organic acids and three phyla, and positive correlations with seven phyla. Organic loading rate and total COD fed also showed significant correlations with microbial community structure, which changed over time. ADM1 predicted a decrease in acetate degraders after a decrease to pH ≤ 6.5. Acidification had a sustained effect on the microbial community and process performance.
欧盟鼓励将秸秆用于生物燃料生产。先前的一项研究表明，使用水解、蒸汽预处理的小麦秸秆，在与黑麦草和苜蓿进行黑暗发酵之前和之后，在升流式厌氧污泥床（UASB）反应器中生产生物甲烷是可行的。本研究提供了这些UASB工艺中微生物群落整体发展情况以及与酸化相关变化的信息。使用高通量扩增子测序分析颗粒样品中的细菌和古菌群落。采用厌氧消化1号模型（ADM1）预测微生物功能组的丰度。测序结果表明，在工艺酸化后，微生物群落的丰富度和多样性降低，细菌相对于古菌的相对丰度降低。典范对应分析表明，有机酸浓度与三个门之间存在显著负相关，与七个门存在正相关。有机负荷率和进料的总化学需氧量也与微生物群落结构存在显著相关性，且微生物群落结构随时间变化。ADM1预测，当pH值降至≤6.5后，乙酸降解菌数量会减少。酸化对微生物群落和工艺性能具有持续影响。
