Structure and Long-Term Stability of the Microbiome in Diverse Diatom Cultures
Structure and Long-Term Stability of the Microbiome in Diverse Diatom Cultures
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DOI：
10.1128/spectrum.00269-21
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发表时间：
2021-09-01
影响因子：
3.7
通讯作者：
Morris, J. Jeffrey
中科院分区：
文献类型：
--
作者：
Barreto Filho, Marcelo Malisano;Walker, Melissa;Morris, J. Jeffrey
微藻培养物通常保持在异生条件下，即，许多研究表明，这些群落都是复杂的，并对目标光合自养生物的生理有重大影响。在这里，我们研究了在连续分批培养的长期维护过程中与硅藻的多样采样相关的微生物组的结构和稳定性。我们发现，与我们最初的预期相反，均匀度多样性随着时间的推移而增加，因为在每个文化中最丰富的类群的优势减少。我们还发现，最初收集培养物的地点和时间对微生物组结构的影响比硅藻物种更大;然而，尽管在地理上有很大的分离，但一些细菌分类群通常存在于大多数培养物中。我们的结果支持了随机初始条件（即，自然界的微生物群落是极其复杂的，在同一个地方共存的物种比不同的资源要多得多。几十年来，理解这种高度多样性的力量一直是生态学和进化理论的中心焦点。在这里，我们使用硅藻的储备培养物，这些硅藻与细菌种群一起持续生长多年，作为自然群落的代表。我们发现，细菌群落多年来保持相对稳定，有证据表明，生态力量的工作，以稳定共存，而不是有利于竞争和排斥。我们还证明，尽管细菌群落存在一些重要的区域差异，但在这些硅藻培养物中可能选择了全球存在的核心微生物组。了解细菌和硅藻之间的相互作用对基础生态科学和实用科学（如工业生物燃料生产）都很重要。
Microalgal cultures are often maintained in xenic conditions, i.e., with associated bacteria, and many studies indicate that these communities both are complex and have significant impacts on the physiology of the target photoautotroph. Here, we investigated the structure and stability of microbiomes associated with a diverse sampling of diatoms during long-term maintenance in serial batch culture. We found that, counter to our initial expectation, evenness diversity increased with time since cultivation, driven by a decrease in dominance by the most abundant taxa in each culture. We also found that the site from which and time at which a culture was initially collected had a stronger impact on microbiome structure than the diatom species; however, some bacterial taxa were commonly present in most cultures despite having widely geographically separated collection sites. Our results support the conclusion that stochastic initial conditions (i.e., the local microbial community at the collection site) are important for the long-term structure of these microbiomes, but deterministic forces such as negative frequency dependence and natural selection exerted by the diatom are also at work.IMPORTANCE Natural microbial communities are extremely complex, with many more species coexisting in the same place than there are different resources to support them. Understanding the forces that allow this high level of diversity has been a central focus of ecological and evolutionary theory for many decades. Here, we used stock cultures of diatoms, which were maintained for years in continuous growth alongside populations of bacteria, as proxies for natural communities. We show that the bacterial communities remained relatively stable for years, and there is evidence that ecological forces worked to stabilize coexistence instead of favoring competition and exclusion. We also show evidence that, despite some important regional differences in bacterial communities, there was a globally present core microbiome potentially selected for in these diatom cultures. Understanding interactions between bacteria and diatoms is important both for basic ecological science and for practical science, such as industrial biofuel production.