Exposing the Dark Microbial Biosphere

摘要: Dark biosphere research has been widely neglected, although by volume this biome comprises the lion’s share of habitats on our planet. In these systems main metabolic strategies are chemotrophic nature, leading to gradual depletion redox gradients essential for sustaining life. Thus environments regarded more or less close chemical equilibrium.Here, we use sequence data whole community metagenomes and taxonomic marker approaches study ecology thermodynamic limit: deep terrestrial aquifers aphotic impacted petroleum- derived products. We show that select individuals with reduced genomes cell sizes, likely as a mode save energy. Due genome reduction, so called “streamlined” cells in number genes pathways. This loss led members sharing burden synthesizing particular energy costly metabolites, creating tight interdependencies between members, consequence. addition, propose scavenging anabolic products from detrital biomass intermediate fermentation equally important systems. Hence, life at limit involves much complex biological system than previously shown, goes beyond traditionally described electron- metabolite-transfer dependencies.This thesis furthermore includes ecological implications, demonstrating how species diversity metabolism shaped dispersal potential contaminated sediments. is also relevant practical point view, it pinpoints new opportunities enhanced bioremediation through metabolite additions order raise efficiency degradation processes.