Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH93FL, UK.
Department of Biology and Center for Advanced Research in Environmental Genomics, University of Ottawa, ON K1N 6N5, Canada.
FEMS Microbiol Ecol. 2017 May 1;93(5). doi: 10.1093/femsec/fix046.
Social interactions have been invoked as potential major selective forces structuring natural microbial communities and thus may help explain the astonishing bacterial diversity of natural ecosystems. Here, we investigate the prevalence and structure of exotoxin-mediated antagonistic interactions among free-living soil Pseudomonas strains collected over the course of 2 years at distances of up to 1 km. Unlike some previous studies on antagonistic interactions among natural isolates, we found the prevalence of exotoxin-mediated inhibitions to be relatively low. When present, antagonistic interactions show a weakly positive relationship with genetic relatedness and metabolic similarity. Isolates sampled from the same growing season were significantly more likely to inhibit each other than they were to inhibit isolates from different growing seasons. Exotoxin-mediated antagonistic interactions between soil pseudomonads thus seem to be structured in time but do not appear to be a major selective force shaping free-living soil bacterial communities of pseudomonads.
社会相互作用被认为是塑造自然微生物群落的潜在主要选择力量，因此可以帮助解释自然生态系统中惊人的细菌多样性。在这里，我们调查了在长达 2 年的时间里，在长达 1 公里的距离内收集的自由生活土壤假单胞菌菌株之间的外毒素介导的拮抗相互作用的普遍性和结构。与以前关于天然分离物之间拮抗相互作用的一些研究不同，我们发现外毒素介导的抑制作用的普遍性相对较低。当存在时，拮抗相互作用与遗传相关性和代谢相似性呈弱正相关。来自同一生长季节的分离物比来自不同生长季节的分离物更有可能相互抑制。因此，土壤假单胞菌之间的外毒素介导的拮抗相互作用似乎是随着时间的推移而构建的，但似乎不是塑造自由生活土壤假单胞菌群落的主要选择力量。
