深海胶红酵母的低温适应性机制初步解析

A preliminary analysis of cold temperature adaptation mechanism of a deep-sea yeast Rhodotorula mucilaginosa

本研究以1株来源于西太平洋雅浦海沟的深海胶红酵母Rhodotorula mucilaginosa CTD02为研究对象,通过对其生理特征测定以及基因组、转录组分析,初步解析深海胶红酵母的低温适应性机制。生长曲线显示,在迟缓期适应之后,菌株可以在4℃低温环境下稳定生长进入对数生长期,体现出对低温环境的良好适应;与常温相比,低温环境下菌株细胞膜脂肪酸组成发生明显变化,不饱和脂肪酸种类和占比增加,达到了90.57%,提示菌株通过提高细胞膜的流动性来适应低温环境;不同温度下的转录组差异表达分析表明,低温上调的基因主要集中在跨膜运输、水解酶等功能,提示低温环境下菌株需要提高营养物质的运输能力来支撑细胞代谢。

Cold temperature adaption mechanism of a deep-sea yeast Rhodotorula mucilaginosa CTD02 isolated from Yap trench of the West Pacific Ocean was studied through determination of physiological characteristics as well as genome and transcriptome analysis.The growth curve showed that after the lag phase,the yeast could grow stably and enter the exponential phase under a cold temperature of 4℃,demonstrating a good adaption to cold temperature environment.The yeast showed a significant change in fatty acid composition of the cell membrane under cold temperature and the types and proportions of unsaturated fatty acids increased(reaching 90.57%),indicating that the yeast could improve the cell membrane fluidity to adapt the cold environment.Transcriptome analysis under different temperatures showed that the up-regulated expression genes under cold temperature were mainly concentrated in the functions such as transmembrane transport and hydrolases,suggesting that the yeast needed to improve the nutrient transport ability to support cell metabolism.