Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, 26129 Oldenburg, Germany.
Environ Microbiol. 2011 Mar;13(3):655-65. doi: 10.1111/j.1462-2920.2010.02371.x. Epub 2010 Nov 15.
Marine macroalgae are constantly exposed to epibacterial colonizers. The epiphytic bacterial patterns and their temporal and spatial variability on host algae are poorly understood. To investigate the interaction between marine macroalgae and epiphytic bacteria, this study tested if the composition of epibacterial communities on different macroalgae was specific and persisted under varying biotic and abiotic environmental conditions over a 2-year observation time frame. Epibacterial communities on the co-occurring macroalgae Fucus vesiculosus, Gracilaria vermiculophylla and Ulva intestinalis were repeatedly sampled in summer and winter of 2007 and 2008. The epibacterial community composition was analysed by denaturing gradient gel electrophoresis (DGGE) and 16S rRNA gene libraries. Epibacterial community profiles did not only differ significantly at each sampling interval among algal species, but also showed consistent seasonal differences on each algal species at a bacterial phylum level. These compositional patterns re-occurred at the same season of two consecutive years. Within replicates of the same algal species, the composition of bacterial phyla was subject to shifts at the bacterial species level, both within the same season but at different years and between different seasons. However, 7-16% of sequences were identified as species specific to the host alga. These findings demonstrate that marine macroalgae harbour species-specific and temporally adapted epiphytic bacterial biofilms on their surfaces. Since several algal host-specific bacteria were highly similar to other bacteria known to either avoid subsequent colonization by eukaryotic larvae or to exhibit potent antibacterial activities, algal host-specific bacterial associations are expected to play an important role for marine macroalgae.
海洋大型藻类经常受到附生细菌的定植。然而，关于宿主藻类上的附生细菌模式及其时空变异性，人们知之甚少。为了研究海洋大型藻类与附生细菌之间的相互作用，本研究通过为期两年的观察，测试了不同大型藻类上附生细菌群落的组成是否具有特异性，以及在不同生物和非生物环境条件下是否能够持续存在。在 2007 年和 2008 年的夏季和冬季，反复采集了共现的大型藻类石莼、泡叶藻和肠浒苔上的附生细菌。通过变性梯度凝胶电泳（DGGE）和 16S rRNA 基因文库分析了附生细菌群落的组成。附生细菌群落的组成不仅在不同的采样间隔中在各藻类物种之间存在显著差异，而且在各藻类物种的细菌门水平上也表现出一致的季节性差异。这些组成模式在连续两年的同一季节再次出现。在同一藻类物种的重复样本中，细菌门的组成在细菌种水平上发生了变化，无论是在同一季节但在不同年份还是在不同季节之间。然而，7-16%的序列被鉴定为与宿主藻类特异性相关的物种。这些发现表明，海洋大型藻类在其表面上具有物种特异性和适应时间的附生细菌生物膜。由于一些藻类宿主特异性细菌与其他已知的避免随后被真核幼虫定植或表现出强烈抗菌活性的细菌高度相似，因此藻类宿主特异性细菌的相互作用有望在海洋大型藻类中发挥重要作用。
