Lipidomic analysis of lactic acid bacteria strains by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

摘要

Analysis by MALDI-TOF mass spectrometry andgas chromatography-mass spectrometry was used tocharacterize the lipid profile of 3 lactic acid bacteriastrains. By gas chromatography coupled with massspectrometry, 23 fatty acids were identified. Dominantacids were palmitic (C16:0), oleic (C18:1), andα-linoleic acid (C18: 3n -3) for Lactobacillus paracasei;for Lactococcus lactis they were palmitic (C16:0), gondoic(C20:1), myristoleic (C14:1), and eicosadienoic acid(C20:2), respectively; and in the case of Lactobacilluscurvatus were C18:1, C18: 2n -6, and C16:0, respectively.The effect of the medium on fatty acid compositionwas also determined. In addition, the fatty acid profilewas also compared using MALDI MS analysis. TheMALDI-TOF MS was used for qualitative analysisand identification of bacterial lipids. Phosphatidylglycerol,phosphatidylethanolamine, phosphatidylinositol,phosphatidylcholine, triacylglycerols, and ceramideswere the most abundant species in lactic acid bacteria.One hundred different combinations of fatty acidsin polar and nonpolar lipids have been identified, including11 phospholipids (18 phosphatidylglycerol, 16phosphatidylethanolamine, 10 phosphatidylinositol, 8phosphatidylcholine, 4 lyso-phosphatidylethanolamine,3 lyso-phosphatidylcholine, 3 phosphatidylserine, 1lyso-phosphatidic acid, 1 lyso-phosphatidylglycerol, 1lyso-phoshatidylinositol, and 1 phosphatidic acid), 23triacylglycerols, 9 ceramides, and 2 sphingomyelin. Themost abundant fatty acids identified were C16:0, C16:1,C18:0, and C18:3. Obtained lipid profiles allowed todistinguish the tested bacterial strains.