Devils Hole Prokaryotes Raw sequence reads
Devils Hole, Bermuda is a shallow inland system that experiences seasonal anoxia. Devils Hole represents a natural laboratory where microbial-driven processes and community succession can be studied in the illuminated water column. The stratification and the development of anoxia along with subsequent overturn and the reoxygenation of the water column has been studied as part of a monthly time-series. As temperature driven stratification occurs, oxygen levels decrease to suboxic levels and DOM accumulates. Simulated overturn experiments were used to recreate mixing; there by assessing the bioavailability of the accumulated dissolved organic carbon to the surface microbial community. The surface prokaryotic community responded to the deep,formerly suboxic, filtrate within six days. The DOM quality changed to less diagenetically altered material and coincided with a community shift to prokaryotes that can both produce fresh dissilved organic carbon via chemoautotrophy and degrade the more recalcitrant DOM. For example, nitrification occurred with an increase in Nitrosopumilales, chemoautotrophic ammonia oxidizing archaea that converted ammonia to nitrite based on the ammonia monooxygenase gene copy number and nutrient data. This study shows that suboxic DOM is bioavailable to surface prokaryotes that in turn drive key processes that influence the carbon and nitrogen cycles.