Cell Membrane Fatty Acid Composition of Chryseobacterium frigidisoli PB4(T), Isolated from Antarctic Glacier Forefield Soils, in Response to Changing Temperature and pH Conditions.
Cell Membrane Fatty Acid Composition of Chryseobacterium frigidisoli PB4(T), Isolated from Antarctic Glacier Forefield Soils, in Response to Changing Temperature and pH Conditions.
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DOI：
10.3389/fmicb.2017.00677
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发表时间：
2017
影响因子：
5.2
通讯作者：
Mangelsdorf K
中科院分区：
文献类型：
--
作者：
Bajerski F;Wagner D;Mangelsdorf K
南极冰川前场的微生物直接暴露在其栖息地恶劣的环境中，其特点是温度极低，地球化学条件不断变化。为了在这些压力条件下生存，微生物需要调整它们的细胞膜脂肪酸库存等。然而，人们对南极土壤环境微生物的适应潜力知之甚少。在这项研究中，我们研究了冷盘金杆菌PB4T细胞膜极性脂肪酸库对温度(0°C到20℃)和pH(5.5到8.5)变化的适应，因为这个从南极冰川中分离出来的新菌株在其详细的生理特征过程中表现出了特定的适应机制。黄杆菌科，包括金杆菌，经常出现在极端的栖息地，如南极洲的无冰绿洲。冷地锦鸡儿在不同的胁迫水平下表现出膜衍生脂肪酸的复杂重组。因此，从20℃到10℃，观察到从较少的ISO-C15：0到较多的ISO-C17：1ω7的变化。在10℃以下，温度适应受Anteiso-FAs的不断增加和iso-FAs的减少的调节。一种不饱和脂肪酸--不饱和脂肪酸-9，13-二烯酸，随着培养温度的降低而不断增加，这凸显了这种脂肪酸对冷藏梭菌适应温度的特殊重要性。关于对不断变化的pH条件的适应，大多数主要脂肪酸在中性pH(pH 6-8)附近显示出恒定的相对比例。主要在pH值极端(pH 5.5和8.5)时观察到强烈的变化。在高pH条件下，短链饱和异构体和异构体FAs增加，而长链不饱和异构体和异构体FAs减少。在低pH值下，则有相反的趋势。这项研究显示了不同膜成分的复杂相互作用，因此为微生物从极端生境到不断变化的环境条件的适应策略提供了深刻的见解。
Microorganisms in Antarctic glacier forefields are directly exposed to the hostile environment of their habitat characterized by extremely low temperatures and changing geochemical conditions. To survive under those stress conditions microorganisms adapt, among others, their cell membrane fatty acid inventory. However, only little is known about the adaptation potential of microorganisms from Antarctic soil environments. In this study, we examined the adaptation of the cell membrane polar lipid fatty acid inventory of Chryseobacterium frigidisoli PB4T in response to changing temperature (0°C to 20°C) and pH (5.5 to 8.5) regimes, because this new strain isolated from an Antarctic glacier forefield showed specific adaptation mechanisms during its detailed physiological characterization. Flavobacteriaceae including Chryseobacterium species occur frequently in extreme habitats such as ice-free oases in Antarctica. C. frigidisoli shows a complex restructuring of membrane derived fatty acids in response to different stress levels. Thus, from 20°C to 10°C a change from less iso-C15:0 to more iso-C17:1ω7 is observed. Below 10°C temperature adaptation is regulated by a constant increase of anteiso-FAs and decrease of iso-FAs. An anteiso- and bis-unsaturated fatty acid, anteiso-heptadeca-9,13-dienoic acid, shows a continuous increase with decreasing cultivation temperatures underlining the particular importance of this fatty acid for temperature adaptation in C. frigidisoli. Concerning adaptation to changing pH conditions, most of the dominant fatty acids reveal constant relative proportions around neutral pH (pH 6–8). Strong variations are mainly observed at the pH extremes (pH 5.5 and 8.5). At high pH short chain saturated iso- and anteiso-FAs increase while longer chain unsaturated iso- and anteiso-FAs decrease. At low pH the opposite trend is observed. The study shows a complex interplay of different membrane components and provides, therefore, deep insights into adaptation strategies of microorganisms from extreme habitats to changing environmental conditions.