Song Ho-Kyung, Song Woojin, Kim Mincheol, Tripathi Binu M, Kim Hyoki, Jablonski Piotr, Adams Jonathan M
Department of Biological Sciences, Seoul National University, Gwanak-Gu, Seoul-151, Republic of Korea.
Seoul Zoo, Seoul Grand Park, 102, Dawgongwongwangjang-ro, Gwancheon-si, Seoul, Korea.
FEMS Microbiol Ecol. 2017 Oct 1;93(10). doi: 10.1093/femsec/fix114.
There is considerable interest in the functional basis of ecological strategies amongst bacteria. We used laboratory microcosms based on culturing of elutant from soil to study the effects of varying initial nutrient concentration, and time succession, on the community metagenome. We found a distinct set of nutrient-related or time-related changes in the functional metagenome. For example, a high nutrient (copiotrophic) strategy was associated with greater abundance of genes related to cell division and cell cycle, while a low nutrient (oligotrophic) strategy had greater abundance of genes related to carbohydrate metabolism and virulence, disease and defense. We also found time-related changes in the functional metagenome, revealing a distinct 'r'-related strategy with greater abundance of genes related to regulation and cell signaling, and a 'K' strategy rich in motility and chemotaxis-related genes. These different gene-based strategies may help to explain how so many bacterial OTUs coexist in nature, and the functional principles dominating natural communities. In terms of diversity, both the OTU richness and the richness of species assignment of functional genes showed linear correlations with functional gene richness, supporting the hypothesis that greater taxonomic diversity is associated with greater functional diversity, with possible implications for ecosystem stability.
细菌生态策略的功能基础备受关注。我们利用基于土壤洗脱液培养的实验室微观世界，研究了初始养分浓度变化和时间演替对群落宏基因组的影响。我们在功能宏基因组中发现了一组与养分或时间相关的明显变化。例如，高养分（富营养型）策略与细胞分裂和细胞周期相关基因的丰度更高有关，而低养分（贫营养型）策略则与碳水化合物代谢以及毒力、疾病和防御相关基因的丰度更高有关。我们还发现了功能宏基因组中与时间相关的变化，揭示了一种与调节和细胞信号传导相关基因丰度更高的独特“r”相关策略，以及一种富含运动性和趋化性相关基因的“K”策略。这些基于基因的不同策略可能有助于解释为何如此多的细菌操作分类单元能在自然界中共存，以及主导自然群落的功能原理。在多样性方面，操作分类单元丰富度和功能基因物种分配丰富度均与功能基因丰富度呈线性相关，支持了分类多样性越高与功能多样性越高相关的假设，这可能对生态系统稳定性具有影响。
