The impact of the starting inoculum on long-term anaerobic digestion performance, process functionality and microbial community composition remains unclear. To understand the impact of starting inoculum, active microbial communities from four different full-scale anaerobic digesters were each used to inoculate four continuous lab-scale anaerobic digesters, which were operated identically for 295 days. Digesters were operated at 15 days solid retention time, an organic loading rate of 1 g COD L_r⁻¹ d⁻¹ (75:25 - cellulose:casein) and 37 °C. Results showed that long-term process performance, metabolic rates (hydrolytic, acetogenic, and methanogenic) and microbial community are independent of the inoculum source. Digesters process performance converged after 80 days, while metabolic rates and microbial communities converged after 120–145 days. The convergence of the different microbial communities towards a core-community proves that the deterministic factors (process operational conditions) were a stronger driver than the initial microbial community composition. Indeed, the core-community represented 72% of the relative abundance among the four digesters. Moreover, a number of positive correlations were observed between higher metabolic rates and the relative abundance of specific microbial groups. These correlations showed that both substrate consumers and suppliers trigger higher metabolic rates, expanding the knowledge of the nexus between microorganisms and functionality. Overall, these results support that deterministic factors control microbial communities in bioreactors independently of the inoculum source. Hence, it seems plausible that a desired microbial composition and functionality can be achieved by tuning process operational conditions.

起始接种物对长期厌氧消化性能，工艺功能和微生物群落组成的影响尚不清楚。为了了解起始接种物的影响，来自四个不同的全规模厌氧消化池的活性微生物群落分别用于接种四个连续的实验室规模的厌氧消化池，它们连续运行295天。消化器在固体停留时间为15天时运行，有机负载率为1 g COD L _r ^-1 d ^-1（75:25-纤维素：酪蛋白）和37°C。结果表明，长期过程性能，代谢率（水解，产乙酸和产甲烷）和微生物群落与接种源无关。消化器的性能在80天后会聚，而代谢率和微生物群落在120-145天后会聚。不同微生物群落向核心社区的融合证明，确定性因素（过程操作条件）是比初始微生物群落组成更强大的驱动力。实际上，核心社区代表了四个消化池相对丰度的72％。此外，在较高的代谢率和特定微生物群的相对丰度之间观察到许多正相关。这些相关性表明，底物的消费者和供应商都触发了更高的代谢率，从而扩大了微生物与功能之间联系的知识。总体而言，这些结果支持确定性因素独立于接种源控制生物反应器中的微生物群落。因此，似乎可以通过调整工艺操作条件来实现所需的微生物组成和功能。