Thermococcus fumicolans and Thermococcus hydrothermalis, Two New Hyperthermophilic Archaea Isolated from Deep-Sea Hydrothermal Vents
Anne GODFROY*, Gerard RAGUENES, Francoise LESONGEUR, Jean-Roch MEUNIER, Jean GUEZENNEC, Elisabeth ANTOINE, Joel QUERELLOU, and Georges BARBIER
IFREMER, DRV/VP, BP70, 29280 Plouzane, France
The extremely thermophilic Archaeum, strain ST557 was isolated from a deep sea hydrothermal vent in the North Fiji Basin (1). This strain is a strictly anaerobic cocci of about 0.8 to 2 μm in diameter. Optimal temperature, pH and sea salt concentration for growth are 90℃, 8.5 and 20 to 40 g/l, respectively. Strain ST557 grows preferentially in presence of elemental sulfur on proteinaceous substrates and on a mixture of the 20 amino acids. It exhibits slow growth on pyruvate and maltose. Growth is inhibited by rifampicin. The DNA G+C content is 54-55 mol%. Sequencing of the 16S rRNA gene indicates that strain ST557 belongs to the Thermococcus genus and is proposed as a new species: Thermococcus fumicolans (3).
The extremely thermophilic Archaeum, strain AL662 was isolated from a deep- sea hydrothermal vent located on the East Pacific Rise at 21°N (4). This strain is a strictly anaerobic coccus, cells are from 0.8 to 2 μm in diameter. The optimum temperature, pH and sea salt concentration for growth are 85℃ and 6 and 20-40 g/liter, respectively. Strain AL662T grows preferentially on proteolysis products, on a mixture of 20 amino acids and on maltose in presence of elemental sulfur. Membrane lipids consist in di and tetraether glycerol lipids. The DNA G+C content is 58%. Sequencing of the 16S rRNA gene showed that strain AL662T belongs to the genus Thermococcus. According to hybridization results we propose that this strain should be placed in a new species, Thermococcus hydrothermalis (2).
1. Antoine, E., Barbier, G., Caprais, J-C., Erauso, G., Godfroy, A., Guezennec, J., Prieur, D., and Raguenes, G. ( 1991 ) Kieler Meeresforsch., 8, 178-181.
2. Godfroy, A., Lesongeur, F., Raguenes, G., Qufirellou, J., Antoine, E., Meunier, J.-R., Guezenned, J., and Barbier, G. (1997) Int. J. Syst. Bacteriol., 47, 622-626.
3. Godfroy, A., Meunier, J.-R., Guezennec J., Lesongeur, F., Raguenes, G., Rimbault, A., and Barbier, G. (1996) Int. J. Syst. Bacteriol., 46, 1113-1119.
4. Raguenes, G., Meunier, J.-R., Antoine, E., Godfroy, A., Caprais, J-C., Lesongeur, F., Guezennec, J., and Barbier, G. (1995) C.R. Acad. Sci. Paris., 318, 395-402.
