Thermococcus barophilus sp. nov., a new barophilic and hyperthermophilic archaeon isolated under high hydrostatic pressure from a deep-sea hydrothermal vent

Abstract

A novel barophilic, hyperthermophilic, anaerobic sulfur-metabolizing archaeon, strain MPT (T = type strain), was isolated from a hydrothermal vent site (Snakepit) on the Mid-Atlantic Ridge (depth, 3550 m). Enrichments and isolation were done under 40 MPa hydrostatic pressure a t 95 "C. Strain MPT was barophilic a t 75,80,85,90,95 and 98 "C, and was an obligate barophile between 95 and 100 "C (TmaX). For growth above 95 "C, a pressure of 15-0-1 7-5 MPa was required. The strain grew a t 48-95 "C under atmospheric pressure. The optimal temperature for growth was 85 "C a t both high (40 MPa) and low (03 MPa) pressures. The growth rate was twofold higher a t 85 "C under in situ hydrostatic pressure compared to at low pressure. Strain MPT cells were motile, coccoid, 08-2-0 pm in diameter and covered b y a hexagonal S-layer lattice. The optimum pH and NaCl concentration for growth a t low pressure were 7.0 and 20-30 g I-', respectively. The new isolate was an obligate heterotroph and utilized yeast extract, beef extract and peptone for growth. Growth was optimal in the presence of elemental sulfur. Rifampicin and chloramphenicol inhibited growth. The core lipids consisted of a major archaeol and a complex lipid pattern consisting of a major phospholipid. The DNA G+C content was 37-1 mol%. Sequencing of the 165 rRNA gene revealed that strain MPT belonged to the genus Thermococcus and it is proposed that this isolate should be designated as a new species, Thermococcus bsrophilus.

Thermococcus gammatolerans sp. nov., a hyperthermophilic archaeon from a deep-sea hydrothermal vent that resists ionizing radiation

“…The optimal pH for growth was determined at 85 uC as described by Marteinsson et al (1999). To determine the optimal NaCl concentration for growth, increasing concentrations of NaCl were added to a medium that contained Isolate EJ3 T was resistant to chloramphenicol, ampicillin, penicillin, kanamycin, vancomycin and streptomycin at a concentration of 150 mg ml 21 , but this isolate was sensitive to rifampicin at the same concentration.…”

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

“…The growth yields of CH1 and 5 Thermococcales strains isolated from samples collected at different depths were determined for increasing hydrostatic pressures: P. furiosus (shallow vent) (Fiala and Stetter, 1986), P. horikoshii (1400 m) (González et al, 1998), P. abyssi (2200 m) (Erauso et al, 1993), P. glycovorans (2650 m) (Barbier et al, 1999) were grown at 95 1C and T. barophilus (3550 m) (Marteinsson et al, 1999) at 85 1C (Figure 1). After 48 h incubation in Thermococcales rich medium maximum growth yields were observed from 1 to 20 MPa for P. furiosus, and from 1 to 30 MPa for P. horikoshii, P. abyssi and P. glycovorans, whereas no growth was observed beyond 35, 50 or 55 MPa, respectively.…”

“…Since the discovery of black smokers in 1979, many thermophilic prokaryotes have been isolated from deep-sea hydrothermal vents, but only Thermococcus barophilus and Marinitoga piezophila (Marteinsson et al, 1999;Alain et al, 2002) are piezophiles, although not obligate. Here, we report the isolation of the first obligate piezo-hyperthermophilic archaeon (Pyrococcus CH1) from the deepest vent field explored so far.…”

Association of Novel Domain in Active Site of Archaic Hyperthermophilic Maltogenic Amylase from Staphylothermus marinus

“…Thus, the functional role of this region in amylase activity is especially interesting. Given the high sequence homology of this extended region among archaic enzymes, it is likely that the CD-hydrolyzing enzymes from hyperthermophilic archaea, such as Staphylothermus hellenicus (46), Thermococcus barophilus (47), Thermococcus kodakarensis (48), Thermococcus onnurineus (49), T. pendens (50), T. volcanium GSS1 (18), and P. furiosus (51), have extra domains with the CBM48 fold.…”