Membrane homeoviscous adaptation in the piezo-hyperthermophilic archaeon Thermococcus barophilus.
Membrane homeoviscous adaptation in the piezo-hyperthermophilic archaeon Thermococcus barophilus.
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DOI：
10.3389/fmicb.2015.01152
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发表时间：
2015
影响因子：
5.2
通讯作者：
Oger PM
中科院分区：
文献类型：
--
作者：
Cario A;Grossi V;Schaeffer P;Oger PM
古细菌嗜热球菌是迄今为止已知的超嗜热压电菌中最极端的成员之一，能够在高达 103°C 的温度和高达 80 MPa 的压力下生长。我们通过高效液相色谱-质谱法分析了 T. barophilus 的膜脂随压力和温度的变化。与之前的报道相反，我们表明，在最佳生长条件（40 MPa，85°C）下，跨膜四醚脂质 GDGT-0（有时称为 caldarchaeol）与 archaeol 一起是 T. barophilus 的主要膜脂。压力增加和温度降低导致古菌的比例增加。相反，在低压和高温条件下观察到更高比例的 GDGT-0。值得注意的是，压力和温度波动也会影响具有不规则聚异戊二烯碳骨架（不饱和番茄烷衍生物）的非极性脂质的不饱和水平，这表明这些中性脂质在 T. barophilus 膜中的结构作用。这些非极性脂质是否插入膜中仍有待解决。然而，我们的结果对这种古细菌和其他含有二醚和四醚脂质混合物的古细菌的膜结构提出了疑问。
The archaeon Thermococcus barophilus, one of the most extreme members of hyperthermophilic piezophiles known thus far, is able to grow at temperatures up to 103°C and pressures up to 80 MPa. We analyzed the membrane lipids of T. barophilus by high performance liquid chromatography–mass spectrometry as a function of pressure and temperature. In contrast to previous reports, we show that under optimal growth conditions (40 MPa, 85°C) the membrane spanning tetraether lipid GDGT-0 (sometimes called caldarchaeol) is a major membrane lipid of T. barophilus together with archaeol. Increasing pressure and decreasing temperature lead to an increase of the proportion of archaeol. Reversely, a higher proportion of GDGT-0 is observed under low pressure and high temperature conditions. Noticeably, pressure and temperature fluctuations also impact the level of unsaturation of apolar lipids having an irregular polyisoprenoid carbon skeleton (unsaturated lycopane derivatives), suggesting a structural role for these neutral lipids in the membrane of T. barophilus. Whether these apolar lipids insert in the membrane or not remains to be addressed. However, our results raise questions about the structure of the membrane in this archaeon and other Archaea harboring a mixture of di- and tetraether lipids.