Department of Plant Biology, University of Illinois, Urbana-Champaign, IL, 61801, USA.
Department of Biology, Indiana University, Bloomington, IN, 47405, USA.
ISME J. 2019 Sep;13(9):2183-2195. doi: 10.1038/s41396-019-0427-7. Epub 2019 May 3.
Microorganisms are strongly influenced by the bottom-up effects of resource supply. While many species respond to fluctuations in the concentration of resources, microbial diversity may also be affected by the heterogeneity of the resource pool, which often reflects a mixture of distinct molecules. To test this hypothesis, we examined resource-diversity relationships for bacterioplankton in a set of north temperate lakes that varied in their concentration and composition of dissolved organic matter (DOM), which is an important resource for heterotrophic bacteria. Using 16S rRNA transcript sequencing and ecosystem metabolomics, we documented strong relationships between bacterial alpha-diversity (richness and evenness) and the bulk concentration and the number of molecules in the DOM pool. Similarly, bacterial community beta-diversity was related to both DOM concentration and composition. However, in some lakes the relative abundance of resource generalists, which was inversely related to the DOM concentration, may have reduced the effect of DOM heterogeneity on community composition. Together, our results demonstrate the potential metabolic interactions between bacteria and organic matter and suggest that changes in organic matter composition may alter the structure and function of bacterial communities.
微生物受到资源供应的自下而上的强烈影响。虽然许多物种对资源浓度的波动有反应，但微生物多样性也可能受到资源库异质性的影响，而资源库通常反映了不同分子的混合物。为了检验这一假设，我们研究了一组北温带湖泊中浮游细菌的资源多样性关系，这些湖泊在溶解有机物 (DOM) 的浓度和组成上有所不同，DOM 是异养细菌的重要资源。通过 16S rRNA 转录测序和生态系统代谢组学，我们记录了细菌α多样性（丰富度和均匀度）与 DOM 库的总浓度和分子数量之间的强烈关系。同样，细菌群落β多样性与 DOM 浓度和组成有关。然而，在一些湖泊中，资源通才的相对丰度与 DOM 浓度呈负相关，这可能降低了 DOM 异质性对群落组成的影响。总之，我们的研究结果表明了细菌和有机物之间存在潜在的代谢相互作用，并表明有机物组成的变化可能改变细菌群落的结构和功能。
