Degradation of amino acids is an important process in methanogenic environments. Early studies in the 1980s focused on isolated clostridia species to study the degradation behaviours. However, it is now well‐recognized that isolated species may not represent those with important roles in situ. This study conducted a continuous enrichment experiment with focus on the comparison of the microbial communities after short‐term enrichment (SE) and long‐term enrichment (LE). Individual amino acids were used as the substrate, and two different anaerobic digester sludge were used as the inoculum. Based on 16S rRNA and 16S rRNA gene, a clear community shift was observed during a time course of 18 months. The SE communities were dominated by microbial populations such as an uncultured Bacteroidales that was different from known fermenters. In the LE communities, known amino acids fermenters were consistently observed with high abundance, including Peptoclostridium acidaminophilum, Acidaminobacter hydrogenoformans and Propionivibrio pelophilus. The community structures could be classified into four types depending on the diversity of fermenters and syntrophs. A culturability index was developed to compare the SE and LE community and revealed that long‐term enrichment tended to select microbial populations closely related to species that has been cultivated whereas larger fractions of the inoculum and SE communities remained uncultured.

中文翻译：

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通过比较短期和长期富集来鉴定厌氧氨基酸降解物。

在产甲烷环境中，氨基酸降解是重要的过程。1980年代的早期研究集中在分离的梭菌物种上，以研究其降解行为。但是，现在人们已经认识到，孤立的物种可能无法代表原地具有重要作用的物种。这项研究进行了一项连续富集实验，重点是比较短期富集（SE）和长期富集（LE）后的微生物群落。单个氨基酸用作底物，两种不同的厌氧消化污泥用作接种物。基于16S rRNA和16S rRNA基因，在18个月的时间过程中观察到了明显的群落转移。SE社区以微生物种群（例如未培养的拟杆菌）为主导。与已知的发酵罐不同。在LE社区中，始终以高丰度持续观察到已知的氨基酸发酵罐，其中包括嗜酸链球菌，氢产酸氨基杆菌和嗜水丙酸杆菌。根据发酵罐和突触菌的多样性，群落结构可分为四种类型。开发了一种可培养性指标来比较SE和LE群落，并揭示了长期富集倾向于选择与已经栽培的物种密切相关的微生物种群，而大部分接种物和SE群落仍未培养。