MONITORING BIOLOGICAL SOIL CRUST REACTIVATION BY FLOW CYTOMETRY AND METAGENOMIC ANALYSIS OF ITS VIRAL COMMUNITY

Viruses are the most abundant biological entities in all ecosystems worldwide. Their ubiquity and dominance on the planet are a measure of their role on the microbial ecology and biogeochemical cycles. In the biological soil crusts (BSC), which are the most important hotspots of microbial evolution and nutrient fluxes in drylands, the role of viruses remained undefined until recently. A novel approach, linking BSC microbial community reactivation to the virus-like particle (VLP) extraction and characterization, was developed. Here we present an innovative method, based on flow cytometry (FCM), to monitor the viable cells in the reactivated BSC under controlled hydration, temperature and light/dark exposure. The BSCs reactivation was aimed to subsequently isolate the associated VLPs, followed by viral DNA extraction and shotgun metagenomic analysis. Finally, this study addressed for the first time a complete description of the BSC-associated virome, shedding the light on the viral abundance, diversity and virus-host interactions in the complex soil matrix.