Pressure and Temperature Effects on Growth and Methane Production of the Extreme Thermophile Methanococcus jannaschii

Abstract

The marine archaebacterium Methanococcus jannaschii was studied at high temperatures and hyperbaric pressures of helium to investigate the effect of pressure on the behavior of a deep-sea thermophile. Methanogenesis and growth (as measured by protein production) at both 86 and 90°C were accelerated by pressure up to 750 atm (1 atm = 101.29 kPa), but growth was not observed above 90°C at either 7.8 or 250 atm. However, growth and methanogenesis were uncoupled above 90°C, and the high-temperature limit for methanogenesis was increased by pressure. Substantial methane formation was evident at 98°C and 250 atm, whereas no methane formation was observed at 94°C and 7.8 atm. In contrast, when argon was substituted for helium as the pressurizing gas at 250 atm, no methane was produced at 86°C. Methanogenesis was also suppressed at 86°C and 250 atm when the culture was pressurized with a 4:1 mix of H2 and C02, although limited methanogenesis did occur when the culture was pressurized with H2.

Temporal and spatial archaeal colonization of hydrothermal vent deposits

“…Microbial 16S rRNA genes detected in our Guaymas subsamples (Methanocaldococcus at 110°C and Desulfurococcaceae at 116°C) were likely exposed to lethal temperatures, as the highest temperature for growth of Methanocaldococcus cultures is 92°C (M. fervens, Jeanthon et al, 1999), and only one Desulfurococcaceae isolate appears to grow at 116°C (Kashefi and Lovley, 2003). These results support studies suggesting that microorganisms colonizing high-temperature deposits can survive at temperatures above their known maximum temperature for growth under high pressures and constant supplies of carbon and energy sources (Miller et al, 1988;Marteinsson et al, 1997;Lloyd et al, 2005;Edgcomb et al, 2007). The large temperature fluctuations recorded within the outer 1 cm of BM4 (Fig.…”

Energetics of overall metabolic reactions of thermophilic and hyperthermophilic Archaea and Bacteria

“…On the other hand, the hyperthermophile Pyrolobus fumarii isolated from a depth of 3650 m from a hydrothermally heated black smoker fragment at the Mid Atlantic Ridge showed no growth enhancement when incubated at 250 bar relative to experiments at 3 bar [9]. In contrast, earlier experiments on M. jannaschii, an autotrophic methanogen from submarine hydrothermal systems, showed a decrease in doubling time from 83 min at 86³C and 7.8 bar to 18 min at the same temperature but 750 bar [26]. At 90³C, in the same study, the doubling time of M. jannaschii decreased from 160 min at 7.8 bar to 50 min at 750 bar.…”

Transcriptional profiling of the hyperthermophilic methanarchaeon Methanococcus jannaschii in response to lethal heat and non‐lethal cold shock

“…Methanococcus jannaschii was obtained from the Oregon Collection of Methanogens and cultivated in 125 ml clear serum bottles (Wheaton) containing 30 ml of media as described previously (Miller et al, 1988) with Na 2 S as the reducing agent. Bottles were inoculated with 3 ml of inoculum and pressurized to 30 psi with a 4:1 v/v mixture of H 2 and CO 2 substrate, then placed in a reciprocal shaking water bath (Precision Scientific Model 25) at 200 oscillations per minute and 85∞C.…”

“…Methanococcus jannaschii is a hyperthermophilic methanarchaeon originally isolated from a submarine hydrothermal vent at a depth of 2600 m on the East Pacific Rise. Initially shown to grow optimally at a temperature of 85 ∞ C and a pH of 6.0 (Jones et al ., 1983), M. jannaschii was later found to exhibit a strong barophilic growth response up to 90 ∞ C with increasing pressures up to 750 atm (Miller et al ., 1988). In 1996, M. jannaschii became the first archaeon to have its complete genome sequenced (Bult et al ., 1996).…”