How the acetate and propionate accumulation impact anaerobic syntrophy during methane formation is not well understood. To investigate such effect, continuous acetate (35 g/L), propionate (11.25 g/L) and bicarbonate (30 g/L) supplementation were used during mesophilic anaerobic digestion. The high throughput sequencing (16S rRNA and mcrA), Real-Time quantitative PCR, and stable carbon isotope fingerprinting were applied to investigate the structure and activity of microbial community members. The results demonstrated that the abundance of syntrophic acetate oxidizing bacteria exhibited a gradual decrease coupled with heavier stable carbon isotopic signature of methane (δ ¹³CH₄) in the three reagents impacted reactors. The increased acetate and propionate concentrations exerted negative influence on biogas production but the relatively stable hydrogenotrophic methanogens together with syntrophic acetate/propionate oxidizing bacteria kept the stable methane formation facing acetate and propionate accumulation. The functional genes copy number of the hydrogenotrophic Methanocellaceae and Methanomicrobiaceae correlated significantly with δ ¹³CH₄ (R² > 0.74), but only the abundance of Methanocellaceae fitted well with δ ¹³CH₄ (p < 0.05). The δ ¹³CH₄ signatures can predict methanogenesis, as it directly reflects the main methanogenic pathway; yet, further investigation of isotope fractionation in acetate/propionate coupled with δ ¹³CH₄ is needed. Collectively, these results provide deep insight into anaerobic syntrophy and reveal changes of synergistic relationships, both of which may contribute to the stability of biogas reactors.

甲烷形成过程中乙酸盐和丙酸盐的积累如何影响厌氧性养分尚不清楚。为了研究这种效果，在中温厌氧消化过程中使用了连续的乙酸盐（35 g / L），丙酸盐（11.25 g / L）和碳酸氢盐（30 g / L）的补充。采用高通量测序（16S rRNA和mcrA），实时定量PCR和稳定的碳同位素指纹图谱来研究微生物群落成员的结构和活性。结果表明，互养乙氧化细菌的丰度显示出加上甲烷更重的稳定碳同位素特征的逐渐降低（δ ¹³ CH ₄）在三种影响反应器的试剂中。乙酸盐和丙酸盐浓度的增加对沼气的产生产生负面影响，但是相对稳定的氢营养型产甲烷菌与乙酸盐/丙酸盐的氧化合能细菌保持稳定的甲烷形成，使其面对乙酸盐和丙酸盐的积累。功能基因复制该氢的数目Methanocellaceae和Methanomicrobiaceae与δ显著相关¹³ CH ₄（R ²  > 0.74），但是只有丰Methanocellaceae装配以及与δ ¹³ CH ₄（p  <0.05）。该δ ¹³ CH_4个信号可以预测甲烷生成，因为它直接反映了主要的甲烷生成途径。然而，进一步的调查同位素分馏在醋酸/丙酸加上δ ¹³ CH ₄是必要的。总的来说，这些结果提供了对厌氧共生的深刻见解，并揭示了协同关系的变化，这两者都可能有助于沼气反应器的稳定性。