Article 4 Mass spectrometry 4 matrix assisted laser desorption ionization time of flight mass spectrometry 4 negative ion electrospray 4 nonhuman 4 positive ion electrospray unclassified drug 4 Acylation 2 Amino Acid Motifs 2 Bacteria 2 Bacterial Proteins 2 Brucella 2 Brucella abortus 2 Brucella suis 2 Cell membranes 2 Core oligosaccharide 2 Glycoproteins 2 Glycoproteomics 2 Glycosylation 2 Gram-negative bacteria 2 L. kefiri 2 Lactobacillus 2 Lactobacillus buchneri 2 Lactobacillus kefiri 2 Lipid A 2 Lipopolysaccharide 2 Lipopolysaccharides 2 MALDI TOF MS 2 MALDI-TOF MS 2 MALDI-TOF mass spectrometry 2