Diversity of Archaea II

Recent studies have revealed three new phyla in the domain Archaea — Thaumarchaeota, Nanoarchaeota, and Korarchaeota.

Thaumarchaeota, like Nitrosopumilus maritimus, are mesophiles thriving in moderate environments and commonly found in terrestrial and aquatic habitats.

They are crucial for the nitrogen cycle since they can oxidize ammonia to nitrate, an essential nutrient for primary producers like plants.

Phylum Nanoarchaeota, currently has a single member Nanoarchaeum equitans. It is hyperthermophilic and found in submarine hot vents.

It possesses the smallest archaeal genome sequenced so far and has genes for repair but lacks those for biosynthesis of macromolecules.

The limited metabolic capabilities of Nanoarchaeum result in its parasitic relationship with the archaeon Ignicoccus.

Korarchaeota like Korarchaeum cryptofilum represent an ancient lineage of archaea that diverged early from the major phyla, Euryarchaeota and Crenarchaeota, as evidenced through phylogenetic and genetic marker analysis.

Typically hyperthermophilic, Korarchaeota members inhabit hot springs, contributing to energy flow and nutrient recycling.