Nutrient supplementation experiments on saltern microbial communities support utilization of DNA as a source of phosphorus

All environments harbor measurable concentrations of dissolved extracellular DNA (eDNA) that can be utilized by microbes as a nutrient. As a result, eDNA plays an important role in global cycles of carbon, nitrogen and phosphorus. However, it remains poorly understood which eDNA components are used, and who in a community utilizes it. To better understand how eDNA influences growth of microbial communities, and to investigate eDNA utilization biases associated with organismal source of eDNA, we conducted microcosm experiments on natural near-saturated hypersaline waters collected from the Isla Cristina solar saltern in southern Spain. The communities were amended by sources of carbon, nitrogen, phosphorus, and DNA, and the community response in each microcosm was tracked via 16S rRNA and rpoB gene sequencing.