Paver Sara F, Youngblut Nicholas D, Whitaker Rachel J, Kent Angela D
Program in Ecology, Evolution, and Conservation Biology, University of Illinois, Urbana, IL, 61801, USA.
Environ Microbiol. 2015 Mar;17(3):816-28. doi: 10.1111/1462-2920.12529. Epub 2014 Jul 9.
Phytoplankton influence the composition of bacterial communities, but the taxonomic specificity of algal-bacterial interactions is unclear due to the aggregation of ecologically distinct bacterial populations by community characterization methods. Here we examine whether phytoplankton seasonal succession affects the composition of subtypes within the cosmopolitan freshwater bacterial genus Polynucleobacter. Changes in the composition of Polynucleobacter subtypes were characterized in samples collected weekly from May to August in 2003 and 2008 from three humic lakes using terminal restriction fragment length polymorphism fingerprinting of the protein-encoding cytochrome c oxidase ccoN gene. Changes in phytoplankton population abundances explained, on average, 30% of temporal variation in the composition of Polynucleobacter subtypes and the interaction between phytoplankton and the environment explained an additional 18% of temporal variation. The effect of phytoplankton on specific Polynucleobacter subtypes was experimentally confirmed by changes in Polynucleobacter subtype composition following incubation with different phytoplankton assemblages or a no-phytoplankton control. Phytoplankton-associated subtypes and differentiation in substrate use among subtypes likely contribute to the effects of phytoplankton on Polynucleobacter subtype composition. Interactions between unique Polynucleobacter populations and phytoplankton highlight the ecological significance and specificity of species interactions in freshwater communities.
浮游植物会影响细菌群落的组成，但由于群落特征分析方法会将生态上不同的细菌种群聚集在一起，藻类与细菌相互作用的分类特异性尚不清楚。在这里，我们研究了浮游植物的季节性演替是否会影响全球淡水细菌属——多核杆菌属内各亚型的组成。2003年和2008年5月至8月期间，每周从三个腐殖质湖泊采集样本，利用编码细胞色素c氧化酶ccoN基因的末端限制性片段长度多态性指纹图谱，对多核杆菌亚型的组成变化进行了表征。浮游植物种群丰度的变化平均解释了多核杆菌亚型组成中30%的时间变化，浮游植物与环境之间的相互作用又额外解释了18%的时间变化。通过将不同的浮游植物组合或无浮游植物对照进行培养后多核杆菌亚型组成的变化，实验证实了浮游植物对特定多核杆菌亚型的影响。与浮游植物相关的亚型以及各亚型在底物利用上的差异可能是浮游植物对多核杆菌亚型组成产生影响的原因。独特的多核杆菌种群与浮游植物之间的相互作用凸显了淡水群落中物种相互作用的生态意义和特异性。
