《科学》阐明多物种微生物群落中的紧急共存

生物如何在群落中共存的问题是生态学家的关键问题。要在自然生态系统中回答这个问题，需要隔离和竞争所有共存成员的艰巨任务。为了使这个问题在实验上易于处理，研究人员从稳定的合成细菌群落中分离出生物，并竞争所有可能的生物对组合，以测试它们共同生活的能力。竞争排斥发生在大多数配对中，而少数配对共存。因此，物种共存部分是相互作用网络的结果，是群落集会的新兴属性，表明了维持生物多样性的重要性。

过去关于微生物共存的工作主要集中在物种对上，但尚不清楚在多物种群落中共存是否需要成对共存。为了解决这个问题，研究团队在体外对12个不同富集群落的稳定共存成员进行了数百次成对竞争实验。为了确定这些实验的结果，团队成员开发了一个自动图像分析管道来量化物种丰度。研究发现竞争性排斥是最常见的结果，而且具有很强的等级性和传递性。由于在稳定的多物种群落中共存的许多物种在相同条件下无法成对共养共存，因此，研究人员得出结论，多物种共存是一种新兴现象。这项工作强调了社区背景对于理解复杂生态系统中共存起源的重要性。

原文：

Understanding the mechanisms that maintain microbial biodiversity is a critical aspiration in ecology. Past work on microbial coexistence has largely focused on species pairs, but it is unclear whether pairwise coexistence in isolation is required for coexistence in a multispecies community. To address this question, we conducted hundreds of pairwise competition experiments among the stably coexisting members of 12 different enrichment communities in vitro. To determine the outcomes of these experiments, we developed an automated image analysis pipeline to quantify species abundances. We found that competitive exclusion was the most common outcome, and it was strongly hierarchical and transitive. Because many species that coexist within a stable multispecies community fail to coexist in pairwise co-culture under identical conditions, we concluded that multispecies coexistence is an emergent phenomenon. This work highlights the importance of community context for understanding the origins of coexistence in complex ecosystems.