Broad Dissemination of Plasmids across Groundwater-Fed Rapid Sand Filter Microbiomes
Rafael Pinilla-Redondo, Asmus Kalckar Olesen, Jakob Russel, Lisbeth Elvira de Vries, Lisbeth Damkjær Christensen, Sanin Musovic, Joseph Nesme, Søren Johannes Sørensen
Abstract
The supply of clean water for human consumption is being challenged by the appearance of anthropogenic pollutants in groundwater ecosystems. Because many plasmids can transfer horizontally between members of bacterial communities, they comprise promising vectors for the dissemination of pollutant-degrading genetic determinants within water purification plants. However, their ability to spread within groundwater-fed rapid sand filters has not been explored. Here, we investigate the transfer dynamics of four transmissible plasmids across rapid sand filter communities originating from three different waterworks in Denmark. Our results revealed a significant ability of natural plasmids to transfer at high frequencies and across distantly related taxa in the absence of plasmid selection, indicating their potential suitability as vectors for the spread of bioremediation determinants in water purification plants. Future work is required to assess the biotechnological applicability and long-term maintenance of exogenous plasmids within sand filter communities.