Environmental Genomics Working Group, Max-Planck Institute for Evolutionary Biology, Plön, Germany
Department of Biology, Suffolk University, Boston, Massachusetts, USA.
Appl Environ Microbiol. 2019 Mar 6;85(6). doi: 10.1128/AEM.02421-18. Print 2019 Mar 15.
A large number of descriptive surveys have shown that microbial communities experience successional changes over time and that ecological dominance is common in the microbial world. However, direct evidence for the ecological processes mediating succession or causing ecological dominance remains rare. Different dispersal abilities among species may be a key mechanism. We surveyed fungal diversity within a metacommunity of pitchers of the model carnivorous plant and discovered that the yeast was ecologically dominant. Its frequency in the metacommunity increased during the growing season, and it was not replaced by other taxa. We next measured its competitive ability in a manipulative laboratory experiment and tracked its dispersal over time in nature. Despite its dominance, is not a superior competitor. Instead, it is a superior disperser: it arrives in pitchers earlier, and disperses into more pitchers, than other fungi. Differential dispersal across the spatially structured metacommunity of individual pitchers emerges as a key driver of the continuous dominance of during succession. Microbial communities are ubiquitous and occupy nearly every imaginable habitat and resource, including human-influenced habitats (e.g., fermenting food and hospital surfaces) and habitats with little human influence (e.g., aquatic communities living in carnivorous plant pitchers). We studied yeast communities living in pitchers of the carnivorous purple pitcher plant to understand how and why microbial communities change over time. We found that dispersal ability is not only important for fungal communities early in their existence, it can also determine which species is dominant (here, the yeast ) long after the species and its competitors have arrived. These results contrast with observations from many human-influenced habitats, in which a good competitor eventually outcompetes good dispersers, since humans often design these habitats to favor a specific competitor. This study will help microbiologists understand the qualities of microbial species that enable takeover of new habitats in both natural and human-influenced environments.
大量描述性调查表明，微生物群落随时间经历演替变化，生态优势在微生物世界中很常见。然而，介导演替或导致生态优势的生态过程的直接证据仍然很少。物种之间不同的扩散能力可能是一个关键机制。我们调查了模型肉食植物捕虫瓶中的真菌多样性，发现酵母 是生态优势种。在生长季节，它在集合群落中的频率增加，并且没有被其他分类群取代。接下来，我们在一个可操纵的实验室实验中测量了它的竞争能力，并在自然界中跟踪了它随时间的扩散。尽管 占据主导地位，但它并不是一个优秀的竞争者。相反，它是一个优秀的扩散者：它比其他真菌更早到达捕虫瓶，并扩散到更多的捕虫瓶中。在个体捕虫瓶的空间结构集合群落中，扩散的差异成为演替过程中 连续占据主导地位的关键驱动因素。微生物群落无处不在，占据着几乎可以想象到的每一个栖息地和资源，包括受人类影响的栖息地（例如，发酵食物和医院表面）和受人类影响较小的栖息地（例如，水生群落生活在肉食植物的捕虫瓶中）。我们研究了生活在肉食性紫色捕虫瓶中的酵母群落，以了解微生物群落是如何以及为何随时间变化的。我们发现，扩散能力不仅对真菌群落的早期生存很重要，而且在物种及其竞争者到达很久之后，它还可以决定哪种物种是优势种（在这里是酵母）。这些结果与许多受人类影响的栖息地的观察结果形成对比，在这些栖息地中，一个好的竞争者最终会胜过好的扩散者，因为人类通常会设计这些栖息地以有利于特定的竞争者。这项研究将帮助微生物学家了解微生物物种的特性，这些特性使它们能够在自然和受人类影响的环境中接管新的栖息地。
