Research Division Biochemical Engineering, Faculty of Technical Chemistry, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria.
Research Group for Mass Spectrometric Bio and Polymer Analytics, Faculty of Technical Chemistry, Institute of Chemical Technologies and Analytics, TU Wien, Vienna, Austria.
Extremophiles. 2020 May;24(3):413-420. doi: 10.1007/s00792-020-01165-1. Epub 2020 Mar 21.
Archaeal lipids are constituted of two isoprenoid chains connected via ether bonds to glycerol in the sn-2, 3 position. Due to these unique properties archaeal lipids are significantly more stable against high temperature, low pH, oxidation and enzymatic degradation than conventional lipids. Additionally, in members of the phylum Crenarchaeota condensation of two (monopolar) archaeal diether lipids to a single (bipolar) tetraether lipid as well as formation of cyclopentane rings in the isoprenoid core strongly reduce permeability of the crenarchaeal membranes. In this work we show that the Crenarchaeum Sulfolobus acidocaldarius changes its lipid composition as reaction to a shift in growth rate caused by nutrient limitation. We thereby identified a novel influencing factor for the lipid composition of S. acidocaldarius and were able to determine the effect of this factor on the lipid composition by using MALDI-MS for the semi-quantification of an archaeal lipidome: a shift in the specific growth rate during a controlled continuous cultivation of S. acidocaldarius from 0.011 to 0.035 h led to a change in the ratio of diether to tetraether lipids from 1:3 to 1:5 and a decrease of the average number of cyclopentane rings from 5.1 to 4.6.
古菌脂类由通过醚键连接在 sn-2、3 位甘油上的两条异戊二烯链组成。由于这些独特的性质，古菌脂类比传统脂类更能耐受高温、低 pH 值、氧化和酶降解。此外，在门 Crenarchaeota 中，两个（单极）古菌双醚脂类缩合成一个（双极）四醚脂类，以及异戊二烯核心中环戊烷环的形成，强烈降低了 crenarchaeal 膜的通透性。在这项工作中，我们表明 Crenarchaeum Sulfolobus acidocaldarius 会根据营养限制引起的生长速率变化而改变其脂类组成。我们因此确定了影响 S. acidocaldarius 脂类组成的一个新因素，并通过 MALDI-MS 对半定量分析古菌脂类组来确定该因素对脂类组成的影响：在对 S. acidocaldarius 的受控连续培养过程中，比生长速率从 0.011 到 0.035 h 的变化导致二醚与四醚脂类的比例从 1:3 变为 1:5，并且平均环戊烷环数量从 5.1 减少到 4.6。
