A single liter of water contains hundreds, if not thousands, of bacterial and archaeal species, each of which typically makes up a very small fraction of the total microbial community (<0.1%), the so-called "rare biosphere." how often, and via what mechanisms, e.g., clonal amplification versus horizontal gene transfer, rare taxa genes contribute to microbial community response environmental perturbations represent important unanswered questions toward better understanding value modeling of diversity. we tested whether species frequently responded changing conditions by establishing 20-liter planktonic mesocosms with water from lake lanier (georgia, usa) perturbing them organic compounds that are rarely detected in lake, including 2,4-dichlorophenoxyacetic acid (2,4-d), 4-nitrophenol (4-np), caffeine. populations degraders these were initially below detection limit quantitative pcr (qpcr) or metagenomic sequencing methods, but they increased substantially abundance after perturbation. several (isolates) time-series data sets revealed distinct cooccurring alleles degradation genes, carried on transmissible plasmids, especially for 2,4-d mesocosms, dominating post-enrichment communities each replicated mesocosm. this diversity also underlies profiles among mesocosms. collectively, results supported hypothesis biosphere can serve as a genetic reservoir, which be missed metagenomics enables caused pollutants, provided insights into size pool species. importance single liter gram soil contains hundreds low-abundance bacterial archaeal species, so called biosphere. astonishing biodiversity ecosystem functioning remains poorly understood, primarily due fact analysis focuses abundant organisms. using combination culture-dependent culture-independent (metagenomics) techniques, showed commonly pollutants. our findings should have implications future studies aim study role processes, bioremediation efforts oil spills other contaminants. copyright © 2017 american society microbiology.
Journal: Applied and environmental microbiology
DOI: 10.1128/AEM.03321-16
Year: 2017