Consortia of low-abundance bacteria drive sulfate reduction-dependent degradation of fermentation products in peat soil microcosms.

摘要: Dissimilatory sulfate reduction in peatlands is sustained by a cryptic sulfur cycle and effectively competes with methanogenic degradation pathways. In series of peat soil microcosms incubated over 50 days, we identified bacterial consortia that responded to small, periodic additions individual fermentation products (formate, acetate, propionate, lactate or butyrate) the presence absence sulfate. Under supplementation, net turnover (ST) steadily increased 16-174 nmol cm(-3) per day almost completely blocked methanogenesis. 16S rRNA gene cDNA amplicon sequencing microorganisms whose increases ribosome numbers strongly correlated ST. Natively abundant (⩾0.1% estimated genome abundance) species-level operational taxonomic units (OTUs) showed no significant response contrast, low-abundance OTUs significantly incubations butyrate. These included members recognized sulfate-reducing taxa (Desulfosporosinus, Desulfopila, Desulfomonile, Desulfovibrio) also are either yet unknown reducers metabolic interaction partners thereof. Most responsive markedly their content but only weakly abundance. Responsive Desulfosporosinus even maintained constantly low population size throughout which suggests novel strategy rare biosphere display activity. Interestingly, two non-sulfate-reducing genus Telmatospirillum (Alphaproteobacteria) contrasting preferences towards butyrate-amended microcosms, corroborating closely related not necessarily ecologically coherent. We show diverse can perform reduction, process exerts control on methane production these climate-relevant ecosystems.