Thermophilic anaerobic digestion (AD) coupled with the pretreatment was used as an alternative method for animal by-product disposal and energy recovery. In this study, the results showed that the cumulative biogas production in T121 thermal pretreatments was slightly lower than that in the Control, while there were no significant differences in the methane content produced between the treatments. Pretreatments with H₂SO₄ at all different concentrations inhibited the anaerobic digestion with lower biogas and methane production due to the high contents of total volatile fatty acids accumulated in the systems. High throughput sequencing analysis showed that pretreatments affected the diversity, community structure and composition of microbial consortia. However, all these treatments harboured the same dominant phylum (Firmicutes) and genus (Coprothermobacter) with active roles during the AD process. These results also suggested that different pretreatments could form their distinct methanogen pathways. Of the treatments, T121 pretreatment increased the relative abundance of methane-producing archaea. The abundance of Methanosarcina was dominated in the thermal pretreatments, suggesting the acetoclastic methanogenesis pathway of methane produced in thermal pretreatments. The abundances of Methanosarcina and Methanothermobacter were nearly the same in the Control and HS4 treatments respectively, indicating that both hydrogenotrophic and acetotrophic methanogen pathways were involved in the HS4 and control treatments. Considering other advantages of pathogen inactivation on pig mortalities, our study could be helpful for the disposal and further optimization of the higher energy recovery of animal carcasses by thermophilic AD coupled with thermal (121 °C) pretreatments.

高温厌氧消化（AD）结合预处理被用作动物副产品处置和能量回收的替代方法。在这项研究中，结果表明，T121热预处理的累积沼气产量略低于对照，而两次处理之间产生的甲烷含量没有显着差异。H ₂ SO ₄预处理在所有不同浓度下，由于系统中积累的总挥发性脂肪酸含量高，抑制了厌氧消化，降低了沼气和甲烷的产生。高通量测序分析表明，预处理影响微生物群落的多样性，群落结构和组成。但是，所有这些治疗在AD过程中都具有相同的显性门（Firmicutes）和属（Coprothermobacter）。这些结果还表明，不同的预处理可以形成其独特的产甲烷菌途径。在这些处理中，T121预处理增加了产甲烷古菌的相对丰度。甲烷八叠球菌的丰富性在热预处理中占主导地位，表明在热预处理中产生的甲烷的乙酰碎裂甲烷生成途径。的丰度甲烷八叠球菌和Methanothermobacter几乎分别在控制和处理HS4相同，表明这两个氢营养和acetotrophic产甲烷途径参与了HS4和对照处理。考虑到病原体灭活对猪死亡率的其他优势，我们的研究可能有助于通过嗜热性AD结合热（121°C）预处理处置和进一步优化动物尸体的更高能量回收率。