Data from: Cold-stress responses in the Antarctic basidiomycetous yeast Mrakia blollopis

Microbes growing at subzero temperatures encounter numerous growth constraints. However, fungi that inhabit cold environments can grow and decompose organic compounds under subzero temperatures. Thus, understanding the cold-adaptation strategies of fungi under extreme environments is critical for elucidating polar-region ecosystems. Here, I report that two strains of the Antarctic basidiomycetous yeast Mrakia blollopis exhibited distinct growth characteristics under subzero conditions: SK-4 grew efficiently, whereas TKG1-2 did not. I analysed the metabolite responses elicited by cold stress in these two M. blollopis strains by using capillary electrophoresis–time-of-flight mass spectrometry. M. blollopis SK-4, which grew well under subzero temperatures, accumulated high levels of TCA-cycle metabolites, lactic acid, aromatic amino acids and polyamines in response to cold shock. Polyamines are recognized to function in cell-growth and developmental processes, and aromatic amino acids are also known to improve cell growth at low temperatures. By contrast, in TKG1-2, which did not grow efficiently, cold stress strongly induced the metabolites of the TCA cycle, but other metabolites were not highly accumulated in the cell. Thus, these differences in metabolite responses could contribute to the distinct abilities of SK-4 and TKG1-2 cells to grow under subzero temperature conditions.

在零下温度环境中生长的微生物会面临诸多生长限制。然而，栖息于寒冷环境的真菌却能够在零下温度下生长并分解有机化合物。因此，解析极端环境下真菌的低温适应策略，对阐明极地生态系统至关重要。
本研究发现，两株南极担子菌酵母Mrakia blollopis在零下条件下表现出截然不同的生长特征：SK-4可高效生长，而TKG1-2则无法有效生长。本研究采用毛细管电泳-飞行时间质谱（capillary electrophoresis–time-of-flight mass spectrometry）技术，分析了这两株M. blollopis在冷胁迫下的代谢物响应特征。在零下温度下生长良好的M. blollopis SK-4，在冷激处理后会大量积累三羧酸循环代谢物、乳酸、芳香族氨基酸以及多胺。已知多胺参与细胞生长与发育过程，而芳香族氨基酸则可在低温环境下促进细胞生长。与之相反，无法高效生长的TKG1-2菌株在冷胁迫下仅会显著诱导三羧酸循环代谢物的积累，而其他代谢物并未在细胞内大量富集。因此，这种代谢响应的差异，可能是SK-4与TKG1-2菌株在零下温度条件下生长能力截然不同的原因所在。