Survival and growth of two heterotrophic hydrothermal vent archaea, Pyrococcus strain GB-D and Thermococcus fumicolans, under low pH and high sulfide concentrations in combination with high temperature and pressure regimes

• Published in: Extremophiles : life under extreme conditions 2007-03, Vol.11 (2), p.329-342
• Main Authors: EDGCOMB, Virginia P, MOLYNEAUX, Stephen J, BOER, Simone, WIRSEN, Carl O, SAITO, Mak, ATKINS, Michael S, LLOYD, Karen, TESKE, Andreas
• Format: Article
• Language: English
• Subjects: Action of physical and chemical agents on bacteria; Archaea; Bacteria; Bacteriology; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; High pressure; High temperature; Hot Temperature; Hydrogen-Ion Concentration; Marine; Microbiology; Oxidation-Reduction; Pressure; Pyrococcus; Pyrococcus - growth & development; Space life sciences; Sulfides; Sulfides - metabolism; Sulfur; Survival; Thermococcales; Thermococcus - growth & development; Thermococcus fumicolans
• ISSN: 1431-0651; 1433-4909
• DOI: 10.1007/s00792-006-0043-0

Growth and survival of hyperthermophilic archaea in their extreme hydrothermal vent and subsurface environments are controlled by chemical and physical key parameters. This study examined the effects of elevated sulfide concentrations, temperature, and acidic pH on growth and survival of two hydrothermal vent archaea (Pyrococcus strain GB-D and Thermococcus fumicolans) under high temperature and pressure regimes. These two strains are members of the Thermococcales, a family of hyperthermophilic, heterotrophic, sulfur-reducing archaea that occur in high densities at vent sites. As actively growing cells, these two strains tolerated regimes of pH, pressure, and temperature that were in most cases not tolerated under severe substrate limitation. A moderate pH of 5.5-7 extends their survival and growth range over a wider range of sulfide concentrations, temperature and pressure, relative to lower pH conditions. T. fumicolans and Pyrococcus strain GB-D grew under very high pressures that exceeded in-situ pressures typical of hydrothermal vent depths, and included deep subsurface pressures. However, under the same conditions, but in the absence of carbon substrates and electron acceptors, survival was generally lower, and decreased rapidly when low pH stress was combined with high pressure and high temperature.