Microorganisms living in deep-oil reservoirs face extreme conditions of elevated temperature and hydrostatic pressure. Within these microbial communities, members of the order Thermotogales are predominant. Among them, the genus Pseudothermotoga is widespread in oilfield-produced waters. The growth and cell phenotypes under hydrostatic pressures ranging from 0.1 to 50 MPa of two strains from the same species originating from subsurface, Pseudothermotoga elfii DSM9442 isolated from a deep African oil-producing well, and surface, P. elfii subsp. lettingae isolated from a thermophilic sulfate-reducing bioreactor, environments are reported for the first time. The data support evidence for the piezophilic nature of P. elfii DSM9442, with an optimal hydrostatic pressure for growth of 20 MPa and an upper limit of 40 MPa, and the piezotolerance of P. elfii subsp. lettingae with growth occurring up to 20 MPa only. Under the experimental conditions, both strains produce mostly acetate and propionate as volatile fatty acids with slight variations with respect to the hydrostatic pressure for P. elfii DSM9442. The data show that the metabolism of P. elfii DSM9442 is optimized when grown at 20 MPa, in agreement with its piezophilic nature. Both Pseudothermotoga strains form chained cells when the hydrostatic pressure increases, especially P. elfii DSM9442 for which 44% of cells is chained when grown at 40 MPa. The viability of the chained cells increases with the increase in the hydrostatic pressure, indicating that chain formation is a protective mechanism for P. elfii DSM9442.

生活在深层油藏中的微生物面临着高温和静水压力的极端条件。在这些微生物群落中，嗜热菌占主导地位。其中，属伪热线虫在油田生产的水域很普遍。来自地下的同一物种的两个菌株在静水压力为0.1至50 MPa的条件下的生长和细胞表型，假单胞菌 从深部非洲产油井和地表分离出DSM9442， P. elfii 亚种 ting科从减少嗜热硫酸盐的生物反应器中分离出来的环境首次被报道。数据支持了嗜盐性的证据P. elfii DSM9442，具有最佳的静水压力，生长压力为20 MPa，上限为40 MPa，压敏电阻为 P. elfii 亚种 ting科最高仅发生20 MPa的增长。在实验条件下，两种菌株均主要产生乙酸和丙酸酯，它们是挥发性脂肪酸，相对于P. elfiiDSM9442。数据表明P. elfiiDSM9442在20 MPa下生长时经过优化，这与其亲压性相符。都伪热线虫 当静水压力增加时，菌株形成链状细胞，特别是 P. elfii在40 MPa下生长时，有44％的细胞链化的DSM9442。链状细胞的活力随着静水压力的增加而增加，这表明链状形成是保护性机制P. elfii DSM9442。