Pyrococcus glycovorans sp. nov., a hyperthermophilic archaeon isolated from the East Pacific Rise.

A hyperthermophilic archaeon, strain AL585T, was isolated from a deep-sea hydrothermal vent located on the East Pacific Rise at latitude 13 degrees N and a depth of 2650 m. The isolate was a strictly anaerobic coccus with a mean cell diameter of 1 micron. The optimum temperature, pH and concentration of sea salt for growth were 95 degrees C, 7.5 and 30 g l-1. Under these conditions, the doubling time and cell yield were 0.5 h and 5 x 10(8) cells ml-1. Strain AL585T grew preferentially in media containing complex proteinaceous carbon sources, glucose and elemental sulfur. The G + C content of the DNA was 47 mol%. Sequencing of the 16S rDNA gene showed that strain AL585T belonged to the genus Pyrococcus and was probably a new species. This was confirmed by total DNA hybridization. Consequently, this strain is described as a new species, Pyrococcus glycovorans sp. nov.