High‐pressure—temperature bioreactor for studying pressure—temperature relationships in bacterial growth and productivity

Abstract

Thermophilic organisms offer many potential advantages for biotechnological processes; however, realization of the promise of thermophiles will require extensive research on bacterial thermophily and high-temperature cultivation systems. This article describes a novel bioreactor suitable for precise studies of microbial growth and productivity at temperatures up to 260 degrees C and pressures up to 350 bar. The apparatus is versatile and corrosion resistant, and enables direct sampling of both liquids and gases from a transparent culture vessel without altering the reaction conditions. Gas recirculation through the culture can be controlled through the action of a magnetically driven pump. Initial studies in this bioreactor of Methanococcus jannaschii, an extremely thermophilic methanogen isolated from a deep-sea hydrothermal vent, revealed that increasing the pressure from 7.8 to 100 bar accelerated the production of methane and cellular protein by this archaebacterium at 90 degrees C, and raised the maximum temperature allowing growth from 90 to 92 degrees C. Further increases in pressure had little effect on the growth rate at 90 degrees C.

Low pressure and desiccation effects on methanogens: Implications for life on Mars

“…Deep down in the Martian subsurface, pressures will be greater than 1 bar, even reaching 300 bar at the lowest subsurface depth where calculations suggest that liquid water can exist (Mellon and Phillips, 2001), and any resident life forms would have to deal with those pressures. High-pressure effects on microbial growth, including a methanogen, Methanococcus jannaschii, have been reported (Miller et al, 1988). The results showed that M. jannaschii demonstrated similar methane production rates at 7.8 and 100 bar using a high-pressure-temperature bioreactor.…”

Pressure effects on the composition and thermal behavior of lipids from the deep-sea thermophile Methanococcus jannaschii

“…For studies at elevated hyperbaric pressure, M. jannaschii was grown in a high-pressure, high-temperature reactor system described elsewhere (21), with the following modifications. To minimize exposure of the culture to potentially reactive metal surfaces, a removable glass liner was fitted inside the stainless steel vessel (25).…”

Extraction of phenolics from Vitis vinifera wastes using non-conventional techniques

“…Beside the extraction, high pressure and temperature perturb bacterial growth (Miller et al, 1988); promote hydrothermal synthesis of graphite tubes (Libera and Gogotsi, 2001) and the synthesis of several compounds (Awana et al, 2007;Marre et al, 2009). To the best of our knowledge HPTE has not been systematically used for polyphenols extraction.…”