The accumulation of low molecular weight cytoprotective compounds (osmolytes) and changes in the membrane lipids composition are of key importance for the adaptation to stress impacts. However, the reason behind the wide variety of osmolytes present in the cell remains unclear. We suggest that specific functions of osmolytes can be revealed by studying the adaptation mechanisms of the mycelial fungus Emericellopsis alkalina (Hypocreales, Ascomycota) that is resistant to both alkaline pH values and high sodium chloride concentrations. It has been established that the fungus uses different osmolytes to adapt to ambient pH and NaCl concentration. Arabitol was predominant osmolyte in alkaline conditions, while mannitol prevailed in acidic conditions. On the salt-free medium mannitol was the main osmolyte; under optimal conditions (pH 10.2; 0.4 M NaCl) arabitol and mannitol were both predominant. Higher NaCl concentrations (1.0-1.5 M) resulted in the accumulation of low molecular weight polyol - erythritol, which amounted up to 12-14%, w/w. On the contrary, changes in the composition of membrane lipids were limited under pH and NaCl impacts; only higher NaCl concentrations led to the increase in the degree of unsaturation of membrane lipids. Results obtained indicated the key role of the osmolytes in the adaptation to the ambient pH and osmotic impacts.

中文翻译：

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渗透剂和膜脂在微菌 Emericellopsis alina 对环境 pH 值和氯化钠的适应中

低分子量细胞保护化合物（渗透剂）的积累和膜脂成分的变化对于适应压力影响至关重要。然而，细胞中存在多种渗透剂的原因尚不清楚。我们建议可以通过研究耐碱性 pH 值和高氯化钠浓度的菌丝体真菌 Emericellopsis alina（Hypocreales，Ascomycota）的适应机制来揭示渗透剂的特定功能。已经确定真菌使用不同的渗透剂来适应环境 pH 值和 NaCl 浓度。阿拉伯糖醇在碱性条件下是主要的渗透剂，而甘露醇在酸性条件下占优势。在无盐培养基上，甘露醇是主要的渗透物；在最佳条件下（pH 10.2；0. 4 M NaCl）阿拉伯糖醇和甘露糖醇都是主要的。较高的 NaCl 浓度 (1.0-1.5 M) 导致低分子量多元醇 - 赤藓糖醇的积累，其含量高达 12-14%，w/w。相反，膜脂组成的变化在 pH 和 NaCl 的影响下受到限制；只有较高的 NaCl 浓度导致膜脂不饱和程度的增加。获得的结果表明渗透剂在适应环境 pH 值和渗透影响中的关键作用。只有较高的 NaCl 浓度导致膜脂不饱和程度的增加。获得的结果表明渗透剂在适应环境 pH 值和渗透影响中的关键作用。只有较高的 NaCl 浓度导致膜脂不饱和程度的增加。获得的结果表明渗透剂在适应环境 pH 值和渗透影响中的关键作用。