Metabolic flexibility allows generalist bacteria to become dominant in a frequently disturbed ecosystem

• DOI: 10.1101/2020.02.12.945220
• Publication Date: 2020-02-13T22:39:25Z
• Authors: Ya-Jou Chen; Pok Man Leung; Sean K. Bay; Philip Hugenholtz; Adam J. Kessler; Guy Shelley; David W. Waite; Perran L. M. Cook; Chris Greening
• Keywords: 0303 health sciences; 03 medical and health sciences; 13. Climate action; 14. Life underwater; 15. Life on land

Abstract Ecological theory suggests that habitat disturbance differentially influences distributions of generalist and specialist species. While well-established for macroorganisms, this has rarely been explored microorganisms. Here we tested these principles in permeable (sandy) sediments, ecosystems with much spatiotemporal variation resource availability other conditions. Microbial community composition function was profiled intertidal subtidal sediments using 16S amplicon sequencing metagenomics, yielding 135 metagenome-assembled genomes. abundance significantly differed sediment depth and, to a lesser extent, sampling date. Several taxa were highly abundant prevalent all samples, including within orders Woeseiales Flavobacteriales; genome reconstructions indicate facultatively anaerobic are metabolically flexible adapt fluctuations by different electron donors acceptors. In contrast, obligately such as sulfate reducers (Desulfobacterales, Desulfobulbales) proposed candidate phylum MBNT15 less overall only thrived more stable deeper sediments. We substantiated findings measuring three metabolic processes sediments; whereas the generalist-associated sulfide oxidation hydrogenogenic fermentation occurred rapidly at depths, specialist-associated process reduction restricted addition, manipulative experiment confirmed generalists outcompete during simulated disturbance. Altogether, suggest become dominant dynamic environments, specialism restricts bacteria narrower niches. Thus, an ecological describing distribution patterns macroorganisms likely extends Such have broad biogeochemical ramifications.