The enigmatic SAR202 cluster up close: shedding light on a globally distributed dark ocean lineage involved in sulfur cycling

• DOI: 10.1038/s41396-017-0009-5
• Publication Date: 2017-11-28T16:29:33Z
• Authors: Maliheh Mehrshad; Francisco Rodrigu...; Mohammad Ali Amoo...; Purificación Lópe...; Rohit Ghai
• Keywords: Bathyal zone; Lineage (genetic); Chloroflexi (class)

The dark ocean microbiota represents the unknown majority in global waters. SAR202 cluster belonging to phylum Chloroflexi was first microbial lineage discovered specifically inhabit aphotic realm, where they are abundant and globally distributed. absence of cultured representatives is a significant bottleneck towards understanding their metabolic capacities role marine environment. In this work, we use combination metagenome-assembled genomes from deep-sea datasets publicly available single-cell construct genomic perspective phylogeny, metabolism biogeography. Our results suggest that members medium sized, free-living cells with heterotrophic lifestyle, broadly divided into two distinct clades. We present evidence vertical stratification these microbes along meso- bathypelagic layers. Remarkably, species highly nearly all deep metagenomic so far. metabolize multiple organosulfur compounds, many appear be sulfite-oxidizers predicted play major sulfur turnover water column. This concomitantly suggests an unsuspected availability nutrient sources allow for high abundance sea.