Key Laboratory of Systems Bioengineering, Ministry of Education and Department of Pharmaceutical Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin, People's Republic of China.
OMICS. 2010 Oct;14(5):553-61. doi: 10.1089/omi.2010.0015.
Metabolomic analysis was carried out to investigate the metabolic differences of diploid (α/a) and homogenous haploid (α,a) yeasts, and further assess their response to ethanol stress. The dynamic metabolic variations of diploid and haploid caused by 3 and 7% (v/v) ethanol stress were evaluated by gas chromatography coupled to time-of-flight mass spectrometry combined with statistical analysis. Metabolite profiles originating from three strains in presence/absence of ethanol stress were distinctive and could be distinguished by principal components analysis. Results showed that the divergence among the strains with ethanol stress was smaller than without it. Furthermore, the levels of most glycolytic intermediates and amino acids in haploid were lower than these in diploid with/without ethanol stress, which was considered as species-specific behaviors. The increases of protective metabolites including polyols, amino acids, precursors of phospholipids, and unsaturated fatty acids under ethanol stress in three strains revealed the ethanol stress-specific responses. Higher fold change in most of these protectants in haploid indicated that haploid was more susceptible to ethanol stress than diploid. These findings provided underlying basis for better understanding diploid and haploid yeasts, and further breeding tolerant strains for efficient ethanol fermentation.
采用代谢组学分析方法，研究了二倍体（α/a）和同质单倍体（α,a）酵母之间的代谢差异，并进一步评估了它们对乙醇胁迫的响应。通过气相色谱-飞行时间质谱联用技术结合统计分析，评估了 3%和 7%（v/v）乙醇胁迫下二倍体和单倍体的动态代谢变化。来自三种菌株的存在/不存在乙醇胁迫的代谢物图谱具有特征性，可通过主成分分析进行区分。结果表明，有乙醇胁迫的菌株之间的差异小于没有乙醇胁迫的菌株。此外，在有/没有乙醇胁迫的情况下，单倍体中的大多数糖酵解中间产物和氨基酸的水平均低于二倍体，这被认为是种特异性行为。在三种菌株中，大多数保护代谢物（包括多元醇、氨基酸、磷脂前体和不饱和脂肪酸）在乙醇胁迫下的增加表明了其对乙醇胁迫的特异性响应。在这些保护剂中，大多数的倍数变化在单倍体中更高，这表明单倍体比二倍体更容易受到乙醇胁迫的影响。这些发现为更好地理解二倍体和单倍体酵母提供了基础，并进一步为高效乙醇发酵培育耐受菌株提供了依据。
