Centre for Marine Bio-Innovation and School of Biological, Earth and Environmental Sciences, The University of New South Wales Sydney, High street Randwick, NSW 2052, Australia.
Carl-von-Ossientzky- Strasse 9-11 Oldenburg, 26111, Germany.
FEMS Microbiol Ecol. 2019 Jun 1;95(6). doi: 10.1093/femsec/fiz060.
Bacterial communities can have an important influence on the function of their eukaryotic hosts. However, how microbiomes are formed and the influence that specific bacteria have in shaping these communities is not well understood. Here, we used the marine diatom Thalassiosira rotula and the algal associated bacterium Phaeobacter inhibens as a model system to explore these questions. We exposed axenic (bacterial-free) T. rotula cultures to bacterial communities from natural seawater in the presence or absence of P. inhibens strain 2.10 or a variant strain (designated NCV12a1) that lacks antibacterial activity. We found that after 2 days the bacterial communities that assembled on the host were distinct from the free-living communities and comprised predominately of members of the Proteobacteria, Bacteroidetes and Cyanobacteria. In the presence of P. inhibens a higher abundance of Alphaproteobacteria, Flavobacteriia and Verrucomicrobia was detected. We also found only minor differences between the communities that established in the presence of either the wild type or the variant P. inhibens strain, suggesting that the antibacterial activity of P. inhibens is not the primary cause of its influence on bacterial community assembly. This study highlights the dynamic nature of algal microbiome development and the strong influence individual bacterial strains can have on this process.
细菌群落可以对其真核宿主的功能产生重要影响。然而，微生物组是如何形成的，以及特定细菌在塑造这些群落方面的影响尚不清楚。在这里，我们使用海洋硅藻塔玛斯罗图拉和藻类相关细菌海杆菌抑制菌作为模型系统来探索这些问题。我们将无菌（无细菌）塔玛斯罗图拉培养物暴露于天然海水中的细菌群落中，存在或不存在抑制菌 2.10 株或缺乏抗菌活性的变异株（指定为 NCV12a1）。我们发现，在 2 天后，组装在宿主上的细菌群落与自由生活的群落不同，主要由变形菌门、拟杆菌门和蓝细菌组成。在海杆菌抑制菌存在的情况下，检测到α变形菌门、黄杆菌门和疣微菌门的丰度更高。我们还发现，在存在野生型或变异型海杆菌抑制菌的情况下，群落之间仅存在微小差异，这表明海杆菌抑制菌的抗菌活性不是其对细菌群落组装影响的主要原因。本研究强调了藻类微生物组发育的动态性质以及单个细菌菌株对这一过程的强烈影响。
