Hydrostatic pressure affects physiology and community structure of marine bacteria during settling to 4000 m: an experimental approach
Hydrostatic pressure affects physiology and community structure of marine bacteria during settling to 4000 m: an experimental approach
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DOI：
10.3354/meps08201
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发表时间：
2009-01-01
影响因子：
2.5
通讯作者：
Gust, Giselher
中科院分区：
文献类型：
--
作者：
Grossart, Hans-Peter;Gust, Giselher
在一个加压的微型宇宙装置中，模拟从表面沃茨到4000 m深度的等温海洋中以1000 m d（-1）下沉，探讨了5株浅水微生物对静水压力变化的响应。技术和方法结合了一个新的，计算机控制的压力实验室与经典和新的遗传工具，以评估选定的细菌菌株的压力反应。大小，数量，生长和物种组成，在一个时间序列模式下定期，非饱和喂养。计划作为一个初始步骤，在寻求定量的静水压力在观察到的海洋微生物分布的作用，从这项研究的结果表明，选定的细菌菌株从表面单独响应压力暴露。一个强大的生理反应导致减少细菌数量的所有菌株在4000米的深度，在文献中的其他地方证实的结果。出乎意料的是，压力变化（下沉过程中）产生的深度特定的最大值和最小值的选定的应变，没有看到在环境压力控制。在加压处理中发生了物种的重新洗牌和所有测试菌株的大小变化。因此，非侵入性的采样功能，而不是端元实验的时间序列实验成为强制性文件的生理反应的压力。我们的研究结果，以及最近的研究结果对深海微生物的生长和群落结构的压力相关的影响，表明在深海微生物有机物周转的估计-不考虑压力相关的影响-需要重新审视。
The response of 5 strains of shallow-water microbes to changing hydrostatic pressure was explored in a pressurized microcosm setup, simulating a sinking at 1000 m d(-1) from surface waters to 4000 m depth in an isothermal ocean. Technology and methods combined a new, computer-controlled pressure laboratory with classical and new genetic tools to evaluate pressure responses of selected bacterial strains. Size, number, growth and species composition were obtained in a time series pattern under regular, non-saturating feeding. Planned as an initial step in a quest for quantifying the role of hydrostatic pressure in observed oceanic microbial distributions, results from this study indicate that selected bacterial strains from the surface respond individually to pressure exposure. A strong physiological response led to reduced bacterial numbers of all strains at 4000 m depth, a result corroborated elsewhere in the literature. Unexpectedly, pressure changes (during sinking) generated depth-specific maxima and minima in number of the selected strains, not seen in the ambient pressure control. A reshuffling of species and changes in sizes of all strains tested occurred in the pressurized treatment. Therefore, time series experiments with non-intrusive sampling features rather than end-member experiments become mandatory to document physiological responses to pressure. Our results, together with recent findings on pressure-related effects on microbial growth and community structure in the deep-sea, indicate that estimates of microbial organic matter turnover in the deep-sea-not taking pressure-related effects into account-need to be revisited.