Untangling Genomes from Metagenomes: Revealing an Uncultured Class of Marine Euryarchaeota

Abstract

Mystery of an Unextreme Microbe Metagenomics has given us glimpses into the huge diversity of microorganisms that are the engines of Earth's elemental cycling. These kinds of surveys can supply a good idea of the dominant organisms in ecosystems, but, because the majority of environmental microbes are difficult to culture and the most abundant organisms swamp metagenomes, it is difficult to discern the functional significance of other contributors. Iverson et al. (p. 587 ) sampled the Puget Sound and developed methods to reconstruct individual genomes from metagenomes, which allowed closure of a genome from the enigmatic marine group II Euryarchaeota . This Archaean is evidently motile, shows signs of extensive gene-swapping with bacteria, and offers some hints to the origin of proteorhodopsin—a molecule that some marine bacteria use to harvest energy from sunlight.