Comprehensive Two-Dimensional Gas Chromatography Time-of-Flight Mass Spectrometry Analysis of Metabolites in Fermenting and Respiring Yeast Cells

• Published in: Analytical chemistry (Washington) Vol. 78; no. 8; pp. 2700 - 2709
• Main Authors: Mohler, Rachel E, Dombek, Kenneth M, Hoggard, Jamin C, Young, Elton T, Synovec, Robert E
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15-04-2006
• Subjects: Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography, Gas - methods; Ethanol - analysis; Ethanol - metabolism; Exact sciences and technology; Factor Analysis, Statistical; Fermentation; Gas chromatographic methods; Glucose - analysis; Glucose - metabolism; Mass Spectrometry - methods; Respiration; Saccharomyces cerevisiae - cytology; Saccharomyces cerevisiae - metabolism; Sensitivity and Specificity; Spectrometric and optical methods; Time Factors; Trehalose - analysis; Trehalose - metabolism; Yeasts - cytology; Yeasts - metabolism; Chemical analysis; Factor analysis; Two dimensional chromatography; Ethanol; Metabolite; Glucose; Gas chromatography; Sample preparation; Time of flight method; Software; Mass spectrometry; Chemometrics; Principal component analysis
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac052106o

Comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry coupled with rapid chemometric analysis were used to identify chemical differences in metabolite extracts isolated from yeast cells either metabolizing glucose (repressed (R) cells) via fermentation or metabolizing ethanol by respiration (derepressed (DR) cells). Principal component analysis (PCA) followed by parallel factor analysis (PARAFAC) in concert with the LECO ChromaTOF software located and identified the differences in composition between the two types of cell extracts and provided a reliable ratio of the metabolite concentrations. In this report, we demonstrate the analytical method developed to provide relatively rapid analysis of three selective mass channels (m/z 73, 205, 387), although in principle all collected mass channels could be analyzed. Twenty-six metabolites that differentiate repressed cells from derepressed cells were identified. The DR/R ratio of metabolite concentrations ranged from 0.02 for glucose to 67 for trehalose. The average biological variation of the sample extracts was 31%. This analysis demonstrates the utility and benefit of using PCA combined with PARAFAC and ChromaTOF software on extremely complex samples to derive useful information from complex three-dimensional chromatographic data objectively and relatively rapidly.