GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
FEMS Microbiol Ecol. 2014 May;88(2):272-9. doi: 10.1111/1574-6941.12292. Epub 2014 Mar 10.
Epibiotic biofilms have the potential to control major aspects of the biology and ecology of their hosts. Their composition and function may thus be essential for the health of the host. We tested the influence of salinity on the composition of epibacterial communities associated with the brown macroalga Fucus vesiculosus. Algal individuals were incubated at three salinities (5, 19, and 25) for 14 days and nonliving reference substrata (stones) were included in the experiment. Subsequently, the composition of their surface-associated bacterial communities was analyzed by 454 pyrosequencing of 16S rRNA gene sequences. Redundancy analysis revealed that the composition of epiphytic and epilithic communities significantly differed and were both affected by salinity. We found that 5% of 2494 epiphytic operational taxonomic units at 97% sequence similarity were responsible for the observed shifts. Epibacterial α-diversity was significantly lower at salinity 5 but did not differ between substrata. Our results indicate that salinity is an important factor in structuring alga-associated epibacterial communities with respect to composition and/or diversity. Whether direct or indirect mechanisms (via altered biotic interactions) may have been responsible for the observed shifts is discussed.
附生生物膜有可能控制其宿主生物学和生态学的主要方面。因此，它们的组成和功能可能对宿主的健康至关重要。我们测试了盐度对与褐藻 Fucus vesiculosus 相关的附生细菌群落组成的影响。将藻类个体在三个盐度（5、19 和 25）下孵育 14 天，并将无生命的参考基质（石头）纳入实验。随后，通过对 16S rRNA 基因序列进行 454 焦磷酸测序分析其表面相关细菌群落的组成。冗余分析表明，附生和附石群落的组成显著不同，并且都受到盐度的影响。我们发现，在 97%序列相似性下，2494 个附生操作分类单元中有 5%负责观察到的变化。在盐度为 5 的情况下，附生细菌 α 多样性显著降低，但在基质之间没有差异。我们的结果表明，盐度是影响藻类相关附生细菌群落组成和/或多样性的重要因素。观察到的变化是直接还是间接机制（通过改变生物相互作用）造成的，还有待讨论。
