Despite the importance of microbial communities in ecosystem functions, the mechanisms underlying the assembly of rare taxa over time are poorly understood. It remains largely unknown whether rare taxa exhibit similar assembly processes to common taxa in local communities. We herein retrieved the 16S rRNA sequences of bacteria collected bimonthly for 2 years from the Pohang wastewater treatment plant. The transient-rare taxa showed different abundance distributions from the common taxa. Transient-rare taxon assemblages also exhibited higher temporal variations than common taxon assemblages, suggesting the distinct ecological patterns of the two assemblages. A multivariate analysis revealed that environmental parameters accounted for 25.3 and 61.6% of temporal variations in the transient-rare and common taxon assemblages, respectively. The fitting of all observed taxa to a neutral community model revealed that 96.4% of the transient-rare taxa (relative abundance, 71.4%) and 73.3% of the common taxa (relative abundance, 45.6%) followed the model, suggesting that stochastic mechanisms were more important than deterministic ones in the assembly of the transient-rare taxa. Collectively, the present results indicate that the transient-rare bacterial taxa at the Pohang wastewater treatment plant differed from the common taxa in ecological patterns, suggesting that dispersal is a key process in their assembly.

中文翻译：

---

跨时间尺度中性地组装了临时稀有细菌类群。

尽管微生物群落在生态系统功能中具有重要意义，但随着时间的流逝，稀有分类单元组装的基本机制仍知之甚少。在当地社区，稀有分类群是否表现出与普通分类群相似的组装过程，这一点在很大程度上仍然未知。我们在这里检索了浦项市污水处理厂每两年两次收集的细菌的16S rRNA序列。瞬时稀有分类单元显示出与普通分类单元不同的丰度分布。瞬态稀少分类群还表现出比普通分类群更高的时间变化，表明这两个集合具有明显的生态模式。多元分析表明，环境参数分别占瞬时稀有和普通分类群中时间变化的25.3％和61.6％。所有观察到的分类单元与中性群落模型的拟合显示，遵循该模型的瞬时稀有分类单元（相对丰度，占71.4％）和普通分类单元的73.3％（相对丰度，占45.6％）均遵循该模型。在瞬态稀有分类单元的组装中，比确定性的重要。总的来说，目前的结果表明，浦项污水处理厂的瞬时稀有细菌类群在生态模式上不同于普通类群，这表明分散是其组装过程中的关键过程。这表明在暂时性稀有生物分类的组装中，随机机制比确定性机制更为重要。总的来说，目前的结果表明，浦项污水处理厂的瞬时稀有细菌类群在生态模式上不同于普通类群，这表明分散是其组装过程中的关键过程。这表明在暂时性稀有生物分类的组装中，随机机制比确定性机制更为重要。总的来说，目前的结果表明，浦项污水处理厂的瞬时稀有细菌类群在生态模式上不同于普通类群，这表明分散是其组装过程中的关键过程。