Pyrococcus CH1, an obligate piezophilic hyperthermophile: extending the upper pressure-temperature limits for life

摘要

A novel hydrothermal site was discovered in March 2007, on the mid-Atlantic ridge during the cruise `Serpentine'. At a depth of 4100 m, the site `Ashadze' is the deepest vent field known so far. Smoker samples were collected with the ROV `Victor 6000' and processed in the laboratory for the enrichment of anaerobic heterotrophic microorganisms under high-temperature and high-hydrostatic pressure conditions. Strain CH1 was successfully isolated and assigned to the genus Pyrococcus, within the Euryarchaeota lineage within the Archaea domain. This organism grows within a temperature range of 80 to 108 °C and a pressure range of 20 to 120 MPa, with optima for 98 °C and 52 MPa respectively. Pyrococcus CH1 represents the first obligate piezophilic hyperthermophilic microorganism known so far. Comparisons of growth yields obtained under hightemperature/high-pressure conditions for relative organisms isolated from various depths, showed clear relationships between depth at origin and responses to hydrostatic pressure.