Correlation of polyunsaturated fatty acids with the cold adaptation of Rhodotorula glutinis
Correlation of polyunsaturated fatty acids with the cold adaptation of Rhodotorula glutinis
复制标题
多不饱和脂肪酸与粘红酵母冷适应的相关性
作者：
He, Jing;Yang, Zhaojie;Zhang, Qi
本研究旨在探讨粘红酵母YM25079的冷适应性与细胞膜流动性、多不饱和脂肪酸含量及(12)-去饱和酶基因表达水平的关系。首先分析了YM25079生长的最适温度，然后用GC-MS检测了YM25079膜脂组分的变化，并用1-苯基-8-磺酸(ANS)荧光法测定了膜的流动性。同时，克隆了YM25079中(12)-脂肪酸去饱和酶的编码序列，并将其转化酿酒酵母INVSCL进行功能分析。用实时定量聚合酶链式反应分析15℃和25℃下(12)-脂肪酸去饱和酶的mRNA表达水平。YM25079能在5~30℃生长，最适培养温度为15℃。当培养温度从25℃降至15℃时，YM25079的膜脂流动性没有明显下降，但亚油酸、亚麻酸等多不饱和脂肪酸的含量从29.4%显著增加到55.39%。此外，从YM25079中成功鉴定和鉴定了一个新的(12)-脂肪酸去饱和酶基因YM25079RGD12，在15℃下生长的YM25079细胞中，该基因的转录水平是25℃时的5倍左右。这些结果表明，粘红酵母YM25079的冷适应可能是由于在多不饱和脂肪酸生物合成过程中，基因，特别是(12)-脂肪酸去饱和酶基因的高表达，从而增加了细胞膜中PUFAs的含量，并在低温下维持了细胞膜的流动性。版权所有(C)2015 John Wiley&Sons，Ltd.
This study aimed to investigate the correlation between the cold adaptation of Rhodotorula glutinis YM25079 and the membrane fluidity, content of polyunsaturated fatty acids and mRNA expression level of the (12)-desaturase gene. The optimum temperature for YM25079 growth was analysed first, then the composition changes of membrane lipid in YM25079 were detected by GC-MS and membrane fluidity was evaluated by 1-anilinonaphthalene-8-sulphonate (ANS) fluorescence. Meanwhile, the encoding sequence of (12)-fatty acid desaturase in YM25079 was cloned and further transformed into Saccharomyces cerevisiae INVScl for functional analysis. The mRNA expression levels of (12)-fatty acid desaturase at 15 degrees C and 25 degrees C were analysed by real-time PCR. YM25079 could grow at 5-30 degrees C, with the optimum temperature of 15 degrees C. The membrane fluidity of YM25079 was not significantly reduced when the culture temperature decreased from 25 degrees C to 15 degrees C, but the content of polyunsaturated fatty acids (PUFAs), including linoleic acid and -Linolenic acid increased significantly from 29.4% to 55.39%. Furthermore, a novel (12)-fatty acid desaturase gene YM25079RGD12 from YM25079 was successfully identified and characterized, and the mRNA transcription level of the (12)-desaturase gene was about five-fold higher in YM25079 cells grown at 15 degrees C than that at 25 degrees C. These results suggests that the cold adaptation of Rhodotorula glutinis YM25079 might result from higher expression of genes, especially the (12)-fatty acid desaturase gene, during polyunsaturated fatty acids biosynthesis, which increased the content of PUFAs in the cell membrane and maintained the membrane fluidity at low temperature. Copyright (c) 2015 John Wiley & Sons, Ltd.