Polar membrane lipids and elemental composition of Thermococcus kodakarensis cells according to growth stage and phosphorus supply

We observed significant changes in the elemental and intact polar lipid (IPL) composition of the archaeon Thermococcus kodakarensis (KOD1) in response to growth stage and phosphorus supply. Reducing the amount of organic supplements and phosphate in growth media resulted in significant decreases in cell size and cellular quotas of carbon (C), nitrogen (N), and phosphorus (P), which coincided with significant increases in cellular IPL quota and IPLs comprising multiple P atoms and hexose moieties. Relatively more cellular P was stored as IPLs in P-limited cells (2-8%) compared to control cells (<0.8%). We also identified a specific IPL biomarker containing a phosphatidyl-N-acetylhexoseamine headgroup that was relatively enriched during rapid cell division. These observations serve as empirical evidence of IPL adaptations in Archaea that will help to interpret the distribution of these biomarkers in natural systems. […]

本研究观察到古菌热球菌（Thermococcus kodakarensis，简称KOD1）的元素组成及完整极性脂质（IPL）结构随生长阶段和磷源供应量的变化而发生了显著变化。在培养基中减少有机补充剂和磷酸盐的用量，导致细胞体积和细胞碳（C）、氮（N）、磷（P）含量显著降低，与细胞IPL含量显著上升及由多个磷原子和己糖基团组成的IPL比例增加相吻合。在磷限制条件下，相较于对照组细胞（<0.8%），细胞内磷更多地以IPL形式储存（2%-8%）。此外，我们还鉴定出一种含有磷脂酰-N-乙酰己糖胺头部基团的特定IPL生物标志物，在快速细胞分裂期间相对富集。这些观察结果为古菌中IPL适应性的实证研究提供了依据，有助于解读这些生物标志物在自然系统中的分布情况。