Background Proteinaceous wastes exhibit high theoretical methane yields and their residues are considered valuable fertilisers. The routine anaerobic degradation of proteins often raises problems like high aromatic compound concentrations caused by the entry of aromatic amino acids into the system. A profound investigation of the consequences of aromatic compound exposure on various microorganisms, which cascade-like and interdependently degrade complex molecules to biogas, is still pending. Results In mesophilic samples, methane was predominantly produced via acetoclastic methanogenesis. The highest positive correlation was observed between phenylacetate (PAA) and Psychrobacter spp. and between phenylpropionate (PPA) and Haloimpatiens spp. Moreover, Syntrophus spp. negatively correlated with PAA (Spearman's rank correlations coefficient (rs) = - 0.46, p < 0.05) and PPA concentrations (rs = - 0.44, p < 0.05) and was also associated with anaerobic benzene ring cleavage. In thermophilic samples, acetate was predominantly oxidised by Tepidanaerobacter spp. or Syntrophaceticus spp. in syntrophic association with a hydrogenotrophic methanogen. The genera Sedimentibacter and Syntrophaceticus correlated positively with both PAA and PPA concentrations. Moreover, Sedimentibacter spp., Tepidanaerobacter spp., Acetomicrobium spp., and Sporanaerobacter spp. were significant LEfSe (linear discriminant analysis effect size) biomarkers for high meso- as well as thermophilic phenyl acid concentrations. Direct negative effects of phenyl acids on methanogenic properties could not be proven. Conclusions Anaerobic phenyl acid formation is not restricted to specific microbial taxa, but rather done by various meso- and thermophilic bacteria. The cleavage of the highly inert benzene ring is possible in methanogenic batch reactors-at least in mesophilic fermentation processes. The results indicated that phenyl acids rather affect microorganisms engaged in preceding degradation steps than the ones involved in methanogenesis.

中文翻译：

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产甲烷、苯酸形成条件下中温和嗜热间歇反应器中的微生物群落动力学。

背景蛋白质废物表现出较高的理论甲烷产量，并且它们的残留物被认为是有价值的肥料。蛋白质的常规厌氧降解通常会引起诸如芳香族氨基酸进入系统引起的高芳香族化合物浓度等问题。对芳香族化合物暴露对各种微生物的影响的深入研究仍然悬而未决，这些微生物将复杂的分子级联并相互依赖地降解为沼气。结果 在中温样品中，甲烷主要是通过醋酸碎甲烷作用产生的。在乙酸苯酯 (PAA) 和 Psychrobacter spp 之间观察到最高的正相关性。以及苯丙酸酯 (PPA) 和 Haloimpatiens spp。此外，Syntrophus spp。与 PAA 呈负相关（Spearman' s 秩相关系数 (rs) = - 0.46, p < 0.05) 和 PPA 浓度 (rs = - 0.44, p < 0.05) 并且还与厌氧苯环裂解有关。在嗜热样品中，乙酸盐主要被温热杆菌属氧化。或 Syntrophaccius spp。与氢营养产甲烷菌共养。Sedimentibacter 和 Syntrophaccius 属与 PAA 和 PPA 浓度呈正相关。此外，Sedimentibacter spp.、Tepidanaerobacter spp.、Acetomicrobium spp.和 Sporanaerobacter spp.。是显着的 LEfSe（线性判别分析效应大小）生物标志物，用于高中间和嗜热苯酸浓度。无法证明苯酸对产甲烷特性的直接负面影响。结论 厌氧苯酸的形成并不局限于特定的微生物类群，而是由各种中温和嗜热细菌完成。高惰性苯环的裂解在产甲烷间歇反应器中是可能的——至少在中温发酵过程中是可能的。结果表明，与参与产甲烷作用的微生物相比，苯酸更能影响参与先前降解步骤的微生物。