Physiological Responses to Stress Conditions and Barophilic Behavior of the Hyperthermophilic Vent Archaeon XXXX .

@entity1 @entity67894 @entity26 @entity3208
The physiology of the deep-sea hyperthermophilic, anaerobic vent archaeon @entity67894 , originating from the Fiji Basin at a depth of 2,000 m, was studied under diverse conditions. The emphasis of these studies lay in the growth and survival of this archaeon under the different conditions present in the natural habitat. Incubation under in situ pressure (20 MPa) and at 40 MPa increased the maximal and minimal growth temperatures by 4(deg)C. In situ pressure enhanced survival at a lethal high temperature (106 to 112(deg)C) relative to that at low pressure (0.3 MPa). The whole-cell protein profile, analyzed by one-dimensional @entity3208 gel electrophoresis, did not change in cultures grown under low or high pressure at optimal and minimal growth temperatures, but several changes were observed at the maximal growth temperature under in situ pressure. The complex lipid pattern of @entity67894 grown under in situ and 0.1- to 0.5-MPa pressures at different temperatures was analyzed by thin-layer chromatography. The phospholipids became more complex at a low growth temperature at both pressures but their profiles were not superimposable; fewer differences were observed in the core lipids. The polar lipids were composed of only one phospholipid in cells grown under in situ pressure at high temperatures. Survival in the presence of @entity26 and under starvation conditions was examined. @entity26 was toxic to @entity67894 at growth range temperature, but the strain survived for several weeks at 4(deg)C. The strain was not affected by starvation in a minimal medium for at least 1 month at 4(deg)C and only minimally affected @entity1 (deg)C for several days. Cells were more resistant to @entity26 in starvation medium. A drastic change in protein profile, depending on incubation time, was observed in cells when starved at growth temperature.
