Abstract
Na.no.pu.sil'lus. Gr. masc. n.
nânos,
a dwarf; L. masc. adj.
pusillus,
very small; N.L. masc. n.
Nanopusillus,
a very small member of the
Nanoarchaeota
.
Nanoarchaeota / Nanobdellia / Nanobdellales / Nanobdellaceae /
Candidatus Nanopusillus
The genus
Candidatus
Nanopusillus is comprised of small coccoid cells (∼100–400 nm) that live epibiotically on the surface of archaeal hosts. The first described species,
Candidatus
Nanopusillus acidilobi, is an anaerobic, hyperthermophilic acidophile whose best growth is observed at 82°C, pH 3.6, cultivated from a hot spring in Yellowstone National Park.
Ca
. Nanopusillus acidilobi cells associate with the
Crenarchaeota
host organism
Acidilobus
sp. 7A. Archaeal flagella (archaella) have been predicted from the genome sequence and shown to be expressed in the proteome. A second putative species,
Candidatus
Nanopusillus massiliensis, was recently reported from human dental plaque and associates with the methanogen
Methanobrevibacter oralis
. The genome consists of a single scaffold which is highly fragmented by spans of ambiguous nucleotides, with 16S rRNA gene fragments from
Bacteria
. Both species have small genomes (∼0.6 Mb) encoding few biosynthetic genes and no apparent ATP synthase complex genes, suggesting that the nanoarchaeotes rely on their host for the production of major cellular precursors.
DNA G + C content (mol%)
: 24 (genome analysis).
Type species
:
Candidatus
Nanopusillus acidilobi
Wurch et al. 2016.