Saharova Sofiya A, Ianutsevich Elena A, Danilova Olga A, Grum-Grzhimaylo Olga A, Groza Nataliya V, Tereshina Vera M
Winogradsky Institute of Microbiology, Research Center of Biotechnology, Russian Academy of Sciences, 33, bld. 2 Leninsky Ave, Moscow, 119071, Russia.
White Sea Biological Station, Faculty of Biology, Lomonosov Moscow State University, 1-12 Leninskie Gory, Moscow, 119234, Russia.
Braz J Microbiol. 2025 Sep 16. doi: 10.1007/s42770-025-01787-7.
To adapt to cold environments, such as the Arctic and Antarctic regions, high mountain peaks, cold soils, deserts, caverns, and cryopegs, fungi employ various strategies. Crucial aspect of this adaptation is maintaining the functions of their cell membranes. To study the mechanisms of cell membrane protection, we analyzed the composition of osmolytes and membrane lipids and their fatty acids in a submerged culture of the psychrotolerant fungus Psychrophilomyces antarcticus during growth at temperatures of 20 °C and 8 °C. The object of the study exhibits a broad growth range from - 3 °C to 27 °C, with an optimal temperature of 20-22.5 °C. For adaptation to cold (8 °C), the fungus significantly increases the degree of unsaturation of phospholipids by enhancing the proportion of α-linolenic acid (40% of the total), compared to the optimal temperature (15% of the total). Additionally, the proportion of sterols in the membrane lipids is twice as low, and the amount of arabitol in the composition of osmolytes is twice as high, compared to the optimal temperature. At both temperatures, the fungus is characterized by the dominance of two osmolytes in the cytosol: trehalose and arabitol. It also shows a predominance of non-bilayer phospholipids, specifically phosphatidic acids (35-42% of the total) and phosphatidylethanolamines (~ 20% of the total), in its membrane lipid composition, along with trace amounts of sterol esters and the formation of mucus in the culture fluid. The combined adjustments in osmolyte and membrane lipid profiles contribute to the fungus' adaptation to a wide range of temperatures. These findings provide insights into the molecular basis of psychrotolerance and open up opportunities for research into potential biotechnological applications.
为了适应寒冷环境，如北极和南极地区、高山之巅、寒冷土壤、沙漠、洞穴和永冻层，真菌采用了各种策略。这种适应的关键方面是维持其细胞膜的功能。为了研究细胞膜保护机制，我们分析了耐低温真菌南极嗜冷菌在20℃和8℃温度下生长时，其渗透溶质和膜脂及其脂肪酸的组成。该研究对象的生长范围很广，从-3℃到27℃，最适温度为20-22.5℃。为了适应寒冷（8℃），与最适温度（占总量的15%）相比，该真菌通过提高α-亚麻酸的比例（占总量的40%）显著增加了磷脂的不饱和度。此外，与最适温度相比，膜脂中甾醇的比例低两倍，渗透溶质组成中阿拉伯糖醇的含量高两倍。在这两个温度下，该真菌的特点是细胞质中两种渗透溶质占主导地位：海藻糖和阿拉伯糖醇。其膜脂组成中还显示非双层磷脂占优势，特别是磷脂酸（占总量的35-42%）和磷脂酰乙醇胺（约占总量的20%），同时培养液中有微量的甾醇酯并形成黏液。渗透溶质和膜脂分布的综合调整有助于该真菌适应广泛的温度范围。这些发现为耐低温性的分子基础提供了见解，并为潜在生物技术应用的研究开辟了机会。
