Genome sequencing of a C. divulgatum strain PM4, novel cell wall-lacking, acidophilic, mesophilic, organotrophic and facultatively anaerobic archaeal strain that have been isolated from acidic streamer formed on the surfaces of copper-containing sulfidic deposits in Mynydd Parys/Parys Mountain, Isle of Anglesey, UK.. Cuniculiplasma divulgatum PM4

Cuniculiplasma divulgatum strain PM4 is acidophilic, mesophilic, facultatively anaerobic, heterotrophic and cell wall-deficient archaea. Generally, all these features are common in the archaea of the order Thermoplasmatales, but PM4 has some certain distinctive traits. Being isolated from sulfide ore mines, this strain did not oxidize any tested iron (II) donors, a common feature in archaea of the family Ferroplasmaceae and potentially anticipated in microorganisms living in these environments. In vitro, strain exhibited mesophilic temperature range for growth. Strain could be characterized as psychrotolerant, due to the growth at temperatures of about 10 °C, which is remarkably low in comparison to characteristics of other thermophilic archaea of the order Thermoplasmatales. The pH optima for growth of both strains were similar to the lowest values recorded for other representatives of Thermoplasmatales and the pH range for growth reflected the environmental conditions at the site of isolation. As in the majority of other organisms from the order Thermoplasmatales, cells of strain PM4 were surrounded by only cytoplasmic membranes. Based on the obligatory use of polypeptides as growth substrates, one can suggest a ‘scavenger’ type lifestyle of these archaea in natural biotopes. Our study aims to give genomic end evolutionary insights into these important features of both currently isolated strains of C. divulgatum.