Nanoarchaeum

Nanoarchaeum is a genus of archaea, a domain of single-celled microorganisms. These organisms are notable for their exceptionally small size, with cells typically measuring around 400 nanometers in diameter, making them some of the smallest known free-living cells. The first species of Nanoarchaeum, Nanoarchaeum equitans, was discovered in 2002 near a hydrothermal vent in the Atlantic Ocean. This species is an obligate symbiont, meaning it relies on a host organism for survival. In this case, N. equitans attaches to the surface of the archaeon Ignicoccus hospitalis, from which it derives essential nutrients and energy.

The genome of Nanoarchaeum is also remarkably small, containing only about 490,000 base pairs and around 500 protein-coding genes. This minimal genome is adapted to its symbiotic lifestyle, lacking many genes involved in basic metabolic processes that are instead provided by its host. The unique characteristics of Nanoarchaeum have made it a subject of significant interest in the field of microbiology, particularly in studies of symbiotic relationships and minimal genomes.

Nanoarchaeum's discovery has challenged traditional views of archaeal diversity and has provided insights into the evolutionary processes that shape microbial life in extreme environments. The study of Nanoarchaeum continues to contribute to our understanding of the complex interactions between microorganisms and their environments.