TY - JOUR
T1 - Liquid chromatography-mass spectrometry for metabolic footprinting of co-cultures of lactic and propionic acid bacteria
AU - Honore, Anders H.
AU - Thorsen, Michael
AU - Skov, Thomas
PY - 2013/10/1
Y1 - 2013/10/1
N2 - Co-cultures of specific lactic and propionic acid bacteria have been shown to have an antagonistic effect against yeast and moulds in dairy systems. In studies of these co-cultures by bioassay-guided fractionation and analysis, numerous compounds have been reported to inhibit yeast and moulds. Although active, the compounds do not account for the full effect observed. Instead, the inhibitory action in the co-culture is believed to be a result of synergy between known exo-metabolites, depletion of nutrients, and/or compounds not yet identified. Untargeted metabolomics or metabolic footprinting could be a potent approach to elucidation of the mechanism. The purpose of this review is to discuss the two pre-requisites for such a study-the compound classes expected in the co-cultures, and on the basis of these, the most suitable analytical technique(s). Ultrahigh-performance liquid chromatography (UPLC) coupled to high-resolution mass spectrometry (MS) via electrospray ionisation (ESI) operated in both positive and negative modes is regarded as the optimum instrumental technique. The applicability of a range of liquid chromatographic techniques ranging from ion-pair (IPC) and hydrophilic interaction (HILIC) to reversed-phase chromatography (RPC) is discussed in terms of the expected metabolome. Use of both HILIC and RPC is suggested, on account of the complementarity of these modes. The most promising strategy uses a combination of the two electrospray polarities and two modes of LC. The strategy recommended in this study does not include all compound classes, and suggestions for supplementary methods are listed.
AB - Co-cultures of specific lactic and propionic acid bacteria have been shown to have an antagonistic effect against yeast and moulds in dairy systems. In studies of these co-cultures by bioassay-guided fractionation and analysis, numerous compounds have been reported to inhibit yeast and moulds. Although active, the compounds do not account for the full effect observed. Instead, the inhibitory action in the co-culture is believed to be a result of synergy between known exo-metabolites, depletion of nutrients, and/or compounds not yet identified. Untargeted metabolomics or metabolic footprinting could be a potent approach to elucidation of the mechanism. The purpose of this review is to discuss the two pre-requisites for such a study-the compound classes expected in the co-cultures, and on the basis of these, the most suitable analytical technique(s). Ultrahigh-performance liquid chromatography (UPLC) coupled to high-resolution mass spectrometry (MS) via electrospray ionisation (ESI) operated in both positive and negative modes is regarded as the optimum instrumental technique. The applicability of a range of liquid chromatographic techniques ranging from ion-pair (IPC) and hydrophilic interaction (HILIC) to reversed-phase chromatography (RPC) is discussed in terms of the expected metabolome. Use of both HILIC and RPC is suggested, on account of the complementarity of these modes. The most promising strategy uses a combination of the two electrospray polarities and two modes of LC. The strategy recommended in this study does not include all compound classes, and suggestions for supplementary methods are listed.
KW - Bacterial co-cultures
KW - Exo-metabolome LC-MS
KW - Modes of separation
U2 - 10.1007/s00216-013-7269-3
DO - 10.1007/s00216-013-7269-3
M3 - Journal article
C2 - 23954995
SN - 1618-2642
VL - 405
SP - 8151
EP - 8170
JO - Analytical and Bioanalytical Chemistry
JF - Analytical and Bioanalytical Chemistry
IS - 25
ER -