Meeting Abstract
The Nanoarchaeota and Korarchaeota represent two poorly characterized, deep-branching archaeal phyla, with very few sequenced genomes. Both lineages have been detected globally in terrestrial and marine high temperature environments but have been very difficult to cultivate in the laboratory. All cultivated Nanoarchaeota form symbiotic/parasitic associations with crenarchaeal hosts, while no Korarchaeota have been grown in pure culture. In order to further characterize their phylogenetic position in the Tree of Life and obtain additional insights into their potential lifestyle, we analyzed the metagenomes of environmental and enrichment cultures containing Korarchaeota and Nanoarchaeota from a New Zealand (NZ) hot spring. Metagenomic libraries were sequenced from the sediment of a hot spring at Tikitere and two enrichment cultures from the same sample. The metagenomes were co-assembled and binned using a differential coverage program, GroopM. The nanoarchaeote draft genome is about 0.55Mb across 55 contigs, with an estimated genome completeness of 86%. The 1.38Mb NZ Korarchaeota draft genome has an estimated completeness of 89% across 151 contigs. The NZ nanoarchaeote genome differs from the marine Nanoarchaeum equitans and is more similar to the other terrestrial nanoarchaeote from Yellowstone National Park, in that it lacks an apparent ATP synthase and appears to be capable of gluconeogenesis amongst other shared features. The draft NZ korarchaeote shares many of the genomic features of Candidatus Korarchaeum cryptofilum. The draft metagenomes provide further evidence to the potential hosts for the NZ nanoarchaeote and possible metabolic capabilities of the NZ korarchaeote.
