Metabolic Diversity within the Globally Abundant Marine Group II Euryarchaea Offers Insight into Ecological Patterns
Benjamin J Tully
Received Date: 1st October 18
Despite their discovery over 25 years ago, the Marine Group II Euryarchaea (MGII) have remained a difficult group of organisms to study, lacking cultured isolates and genome references. The MGII have been identified in marine samples from around the world and evidence supports a photoheterotrophic lifestyle combining phototrophy via proteorhodopsins with the remineralization of high molecular weight organic matter. Divided between two clades, the MGII have distinct ecological patterns that are not understood based on the limited number of available genomes. Here, I present the comparative genomic analysis of 250 MGII genomes, providing the most detailed view of these mesophilic archaea to-date. This analysis identified 17 distinct subclades including nine subclades that previously lacked reference genomes. The metabolic potential and distribution of the MGII genera revealed distinct roles in the environment, identifying algal-saccharide-degrading coastal subclades, protein-degrading oligotrophic surface ocean subclades, and mesopelagic subclades lacking proteorhodopsins common in all other families. This study redefines the MGII and provides an avenue for understanding the role these organisms play in the cycling of organic matter throughout the water column.
Read in full at bioRxiv.
This is an abstract of a preprint hosted on an independent third party site. It has not been peer reviewed but is currently under consideration at Nature Communications.