Temperature is the critical factor affecting the efficiency and cost of anaerobic digestion (AD). The current work develops a shift-temperature AD (STAD) between 35 °C and 55 °C, intending to optimise microbial community and promote substrate conversion. The experimental results showed that severe inhibition of biogas production occurred when the temperature was firstly increased stepwise from 35 °C to 50 °C, whereas no inhibition was observed at the second warming cycle. When the organic load rate was increased to 6.37 g VS/L/d, the biogas yield of the STAD reached about 400 mL/g VS, nearly double that of the constant-temperature AD (CTAD). STAD promoted the proliferation of Methanosarcina (up to 57.32 %), while severely suppressed hydrogenophilic methanogens. However, when the temperature was shifted to 35 °C, most suppressed species recovered quickly and the excess propionic acid was quickly consumed. Metagenomic analysis showed that STAD also promoted gene enrichment related to pathways metabolism, membrane functions, and methyl-based methanogenesis.

中文翻译：

---

培养中温厌氧消化微生物群落的循环变温操作方法


温度是影响厌氧消化（AD）效率和成本的关键因素。目前的工作开发了 35 °C 至 55 °C 之间的变温 AD (STAD)，旨在优化微生物群落并促进底物转化。实验结果表明，当温度首次从35℃逐步升高到50℃时，沼气产生受到严重抑制，而在第二次升温循环时没有观察到抑制作用。当有机负荷率增加到6.37 g VS/L/d时，STAD的沼气产量达到约400 mL/g VS，几乎是恒温AD（CTAD）的两倍。 STAD促进了甲烷八叠球菌的增殖（高达57.32%），同时严重抑制了亲氢产甲烷菌。然而，当温度升至35°C时，大多数受抑制的物种迅速恢复，过量的丙酸很快被消耗。宏基因组分析表明，STAD 还促进与代谢途径、膜功能和基于甲基的产甲烷作用相关的基因富集。