Metabolic fingerprinting of Lactobacillus paracasei: a multi-criteria evaluation of methods for extraction of intracellular metabolites

Anal Bioanal Chem. 2015 Aug;407(20):6095-104. doi: 10.1007/s00216-015-8783-2. Epub 2015 May 29.

Abstract

An untargeted multi-criteria approach was used to select the best extraction method among freeze-thawing in methanol (FTM), boiling ethanol (BE) and chloroform-methanol (CM) for gas chromatography mass spectrometry (GC-MS) metabolic fingerprinting of Lactobacillus paracasei subsp. paracasei (CRL-431®). The following results were obtained: (i) coverage and efficiency, measured by the number of features extracted and the sum of feature intensities, showed that FTM extraction resulted in the largest compound coverage with a total number of features 8.9 × 10(3) ± 0.5 × 10(3), while merely 6.6 × 10(3) ± 0.9 × 10(3) and 7.9 × 10(3) ± 0.8 × 10(3) were detected in BE or CM, respectively; (ii) the similarity of extraction methods, measured by common features, demonstrated that FTM yielded the most complementary information to BE and CM; i.e. 17 and 33 % of the features of FTM extracted were unique compared to CM and BE, respectively; and (iii) a clear-cut separation according to extraction method was demonstrated by assessment of the metabolic fingerprints by pixel-based data analysis. Indications of metabolite degradation were observed under the elevated temperature for BE extraction. A superior coverage of FTM together with a high repeatability over nearly the whole range of GC-amenable compounds makes this the extraction method of choice for metabolic fingerprinting of L. paracasei.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chloroform / chemistry
  • Freezing
  • Gas Chromatography-Mass Spectrometry / methods*
  • Lactobacillus / chemistry
  • Lactobacillus / metabolism*
  • Metabolome*
  • Metabolomics / methods*
  • Methanol / chemistry
  • Solvents / chemistry
  • Transition Temperature

Substances

  • Solvents
  • Chloroform
  • Methanol