Qinghai Key Laboratory of Vegetable Genetics and Physiology, Academy of Agriculture and Forestry Sciences, Qinghai University, Ningda Road 253, Xining, 810016, Qinghai, China.
Arch Microbiol. 2022 Feb 22;204(3):188. doi: 10.1007/s00203-022-02796-y.
In this study, gas production from mixed anaerobic fermentation of rapeseed cake and sheep manure at low temperature (15.2-17.8 °C) was investigated in Qinghai rural household biogas digesters to understand the temporal dynamics of key microbial populations involved in fermentations. Different raw material ratios resulted in significantly different effects on biogas yields and microbial community compositions over 40 days. When the dry weight ratio of sheep manure to rapeseed cake was 1:2, the highest level of cumulative gas production was observed (122.92 m·t). Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria were the dominant bacterial phyla among the 29 digester samples (total relative abundances > 79.23%), followed by Synergistetes (4.09-10.7%). Lactobacillus was the most abundant genus in the biogas digesters with high rapeseed cake contents (average relative abundances: 14.68%), while Peptoniphilus exhibited higher abundances (12.69%) in the mixed treatments. In addition, unclassified Synergistaceae abundances (6.64%) were positively associated with biogas production variation among treatments. Bacteroides (5.74%) and Pseudomonas (5.24%) both accounted for larger proportions of communities in the digesters that used more sheep manure. Methanomicrobiales (66.55%) was the most dominant archaeal group among digesters, with Methanogenium (41.82%) and Methanoculleus (16.55%) representing the main gas-producing archaeal genera; they were more abundant in biogas digesters with higher sheep manure contents and higher rapeseed cake contents, respectively. VFAs and pH were the main factors associated with differences in microbial communities among the 29 samples. Specifically, VFA concentrations were positively correlated with Lactobacillus, Methanoculleus and Methanothrix abundances, while pH was positively correlated with Bacteroides, Pseudomonas, and Methanobacterium abundances.
本研究在青海农村户用沼气池内研究了油菜籽饼和羊粪在低温（15.2-17.8°C）条件下混合厌氧发酵产生的沼气，以了解参与发酵的关键微生物种群的时间动态。不同的原料比对 40 天内的沼气产量和微生物群落组成有显著不同的影响。当羊粪与油菜籽饼的干重比为 1:2 时，累积产气量最高（122.92m·t）。厚壁菌门、变形菌门、拟杆菌门和放线菌门是 29 个发酵罐样品中的主要细菌门（总相对丰度 > 79.23%），紧随其后的是互养菌门（4.09-10.7%）。在油菜籽饼含量较高的沼气发酵罐中，乳杆菌是最丰富的属（平均相对丰度：14.68%），而在混合处理中，噬淀粉菌属的丰度较高（12.69%）。此外，未分类的互养菌科的丰度（6.64%）与处理间沼气产量的变化呈正相关。拟杆菌属（5.74%）和假单胞菌属（5.24%）在使用更多羊粪的发酵罐中，在群落中所占的比例更大。甲烷微菌门（66.55%）是发酵罐中最主要的古菌群，其中产甲烷菌属（41.82%）和甲烷八叠球菌属（16.55%）代表主要的产甲烷古菌属；它们在羊粪含量和油菜籽饼含量较高的沼气发酵罐中更为丰富。VFAs 和 pH 是导致 29 个样本中微生物群落差异的主要因素。具体而言，VFA 浓度与乳杆菌属、甲烷八叠球菌属和甲烷丝状菌属的丰度呈正相关，而 pH 与拟杆菌属、假单胞菌属和甲烷杆菌属的丰度呈正相关。
