PNNL

Abstract

Single stranded DNA viruses have been previously shown to populate the oceans on a global scale, and to be endemic in microbialites of both marine and freshwater systems. We undertook for the first time direct viral metagenomic shotgun sequencing to explore the diversity and abundances of viruses in the modern stromatolites of Shark Bay Australia. The data indicate that Shark Bay marine stromatolites have similar abundances of ssDNA viruses to that of Highbourne Cay, Bahamas. While ssDNA viruses dominate both these systems, both Shark Bay and Highbourne Cay also have unique endemic viruses found only within a given ecosystem. Further, we assembled pyrosequencing data from the Shark Bay systems into six unique viral genomes; four that have no homologs in any database. Shark bay stromatolites harbor endemic viruses that may play key roles in modulating microbial diversity as well as potentially impacting ecosystem function.