Metabolomic Analysis

Brief Description:

Metabolomics is the study of the small-molecule metabolite profiles.  The metabolome represents the collection of all metabolites in a biological cell, tissue, organ, or organism.  This technique is similar to mRNA and proteomic analyses, but investigates all compounds present instead of a single class.  Proteomic analysis shows what proteins are present, but cannot show which are active or the degree of activity.  Analysis of mRNA presence shows what sequences are being copied, but cannot show if or how many proteins are being made and what they are doing in the cell.  Metabolomics can be used to analyze the presence and quantity of small molecules under different conditions to study a biological system’s response to environmental conditions.  If the genome specifies the transcriptome, which specifies the proteome, which specifies the metabolome, then the metabolome specifies the phenotype.

Analyses used to assay the metabolome include HPLC/MS, GC/MS, ICP-MS, Infusion, CEMS, MALDI, and FTIR among others.  Each of these techniques specializes in the compounds that it can detect and cannot detect all compounds in a single run.  For example, different columns must be used to assay polar and non-polar compounds in GC/MS.  Since metabolomics is interested in assaying all present compounds, multiple analysis techniques must be used.  Cost and amount of time required can get out of control quickly.  Metabolomics can be done on a solution of compounds, but it can also be assayed in two dimensions.  Liver and brain slices have been assayed to determine compound concentration and presence in specific areas of the organ.

Application in Wine Microbiology:

Studying the metabolome can be useful in winemaking to determine impact compounds in wine as well to assay environmental effects on the microbes presents. Yeast and bacteria, spoilage or inoculated, the microbe metabolomes interact with the wine metabolome to form a complicated mixture. Kirsten Skogerson in the Fiehn Lab here at Davis is using metabolomics to correlate body in white wines to specific compounds.

References:

  • 2008. Metabolomics: Wine-omics. Nature. 455: 699. <http://www.bmrb.wisc.edu/metabolomics/>.
  • Lindon, J.C., J.K. Nicholson, E. Holmes. 2007 Handbook of Metabonomics and Metabolomics. Elsevier. Amsterdam, The Netherlands
  • Trengrove, R. "Murdoch University Metabolomics Research and Metabolomics Australia." University of California, Davis, Davis. 25 Feb. 2010. Lecture.