In contrast to mesophiles, in which levels of trehalose and phosphatidic acids (PA) increased only under heat shock (HS), in thermophiles trehalose and PA were predominant under optimal growth conditions. To study the role of trehalose protection in the adaptation of thermophiles to various stressors, the composition of osmolytes and membrane lipids in the thermophilic fungus Rhizomucor miehei was studied under cold (CS), osmotic (OS) and oxidative (OxS) shocks. CS resulted in no accumulation of glycerol in the mycelium, while the amount of trehalose decreased. The main lipid changes were the increase in the PA proportion with simultaneous decrease of sterols (St), the increase of the unsaturation degree of polar lipids and the decrease of the ergosterol proportion in total St. OS did not cause changes in the lipid composition, but led to the decrease of ergosterol proportion too. Despite the low ability of Mucorales to produce polyols, increase in the level of arabitol and glycerol was observed under OS. OxS led to the decrease of trehalose level and had no effect on the lipid composition. Thus, our results show the similarity (OS) and the difference (CS and OxS) between adaptation mechanisms of thermophiles and mesophiles.

中文翻译：

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嗜热真菌Rhizomucor miehei对冷，渗透和氧化休克的适应性反应中的渗透液和膜脂。

与仅在热休克（HS）下海藻糖和磷脂酸（PA）的水平升高的嗜温菌相反，嗜热菌中海藻糖和PA在最佳生长条件下占主导地位。研究海藻糖保护在嗜热菌适应各种应激源，嗜热真菌Rhizomucor miehei中渗透压物和膜脂质的组成中的作用在冷（CS），渗透（OS）和氧化（OxS）冲击下进行了研究。CS导致菌丝体中没有甘油的积累，而海藻糖的量减少了。主要的脂质变化是PA比例增加，同时固醇（St）减少，极性脂质的不饱和度增加，麦角固醇比例在总St. OS中的降低并未引起脂质组成的变化，但也导致麦角固醇比例降低。尽管Mucorales能力低下为了生产多元醇，在OS下观察到阿拉伯糖醇和甘油的水平增加。OxS导致海藻糖水平降低，对脂质组成没有影响。因此，我们的结果表明嗜热菌和嗜温菌适应机制之间的相似性（OS）和差异（CS和OxS）。