对数生长期酿酒酵母胞内代谢情况分析

Analysis of intracellular metabolism of Saccharomyces cerevisiae in logarithmic growth stage

酿酒酵母是发酵产业中的关键微生物,处于对数生长期的酵母菌迅速繁殖,积累大量初级代谢产物,对此时期进行调控可以提高发酵效率。为了解对数生长期酿酒酵母发酵情况,采用液相色谱串联质谱法(liquid chromatography tandem mass spectrometry,LC-MS/MS)对酵母胞内主要代谢物及其代谢途径进行分析。结果表明,在对数生长期酿酒酵母胞内共鉴定927种代谢物,含氮和含硫化合物数量及相对含量均最高。这些代谢物参与的代谢途径中,核苷酸代谢、辅因子和维生素代谢、碳水化合物代谢以及氨基酸代谢为酿酒酵母主要代谢途径,核苷酸代谢中相对含量最高的为嘧啶代谢。代谢物和代谢途径主要涉及酵母细胞膜的构建,遗传信息的复制,信号分子的传递,渗透压的调节等。为酵母提供生长所需的基本小分子物质和能量,同时为合成蛋白质、核酸等生物大分子物质提供原料。此外,碳水化合物和氨基酸代谢的代谢流分布可更好地支持酿酒酵母进行核苷酸代谢,促进酵母菌的增殖、生长和存活。该研究结果为定向改造酿酒酵母、提高其发酵效率提供一定科学依据。

Saccharomyces cerevisiae is a key microorganism in the fermentation industry.During the logarithmic growth period,yeasts proliferate rapidly and accumulate a large amount of primary metabolites.Regulating this period can improve the fermentation efficiency.In order to understand the fermentation of S.cerevisiae in the logarithmic growth period,the main metabolites and metabolic pathways were analyzed by liquid chromatography tandem mass spectrometry(LC-MS/MS).The results showed that 927 metabolites were identified,a-mong which the quantity and relative content of compounds containing nitrogen and sulfur were the highest.Among the metabolic pathways involved in these metabolites,nucleotide metabolism,carbohydrate metabolism,cofactor and vitamin metabolism and amino acid metabo-lism were the main metabolic pathways of S.cerevisiae,and the relative abundance of pyrimidine metabolism was the highest in nucleotide metabolism.Metabolites and metabolic pathways mainly involved the construction of yeast cell membrane,the replication of genetic infor-mation,the transmission of signal molecules,the regulation of osmotic pressure,and so on.These metabolic processes provided basic small molecular substances and energy for yeast growth,and also provided raw materials for the biosynthesis of biological macromolecules such as protein and nucleic acid.In addition,the metabolic flow distribution of carbohydrate and amino acid metabolism could better sup-port the nucleotide metabolism of S.cerevisiae and promote the proliferation,growth,and survival of S.cerevisiae.The results provided a scientific basis for the directional transformation of S.cerevisiae and the improvement of its fermentation efficiency.