title: Identification and quantification of lichenysin - a possible source of food poisoning.
abstract: Lichenysin produced by 53 different Bacillus licheniformis strains has been structurally examined with a qualitative liquid chromatography-tandem mass spectrometry (LC-MS/MS) method using quadrupole-time-of-flight mass spectrometry. The same lichenysin isoforms are produced from all strains, indicating that the growth conditions have a stronger influence on the lipopeptide production than the genotype. A rapid method for the quantification of lichenysin from bacterial cell cultures with LC-MS/MS after a simple methanol extraction has been refined. For the first time commercially available lichenysin has been used as calibrant, making quantification more accurate. The trueness for C15-lichenysin has been improved to 94% using matrix-matched calibration with lichenysin compared with 30% using solvent calibration with surfactin. The quantitative method was fully validated based on Commission Decision 2002/657/EC. The LOD of the method was below 1 µg g(-1) and the repeatability ranged from 10% to 16%.
authors.affiliation: a School of Veterinary Science , Norwegian University of Life Sciences , Oslo , Norway.
authors.forename: Helene Thorsen
authors.initials: HT
authors.lastname: Rønning
authors.affiliation: b Forsvarets forskningsinstitutt FFI , Norwegian Defence Research Establishment , Kjeller , Norway.
authors.forename: Elisabeth Henie
authors.initials: EH
authors.lastname: Madslien
authors.affiliation: a School of Veterinary Science , Norwegian University of Life Sciences , Oslo , Norway.
authors.forename: Tone Normann
authors.initials: TN
authors.lastname: Asp
authors.affiliation: a School of Veterinary Science , Norwegian University of Life Sciences , Oslo , Norway.
authors.forename: Per Einar
authors.initials: PE
authors.lastname: Granum
mesh_terms: D001407:Bacillus / Q000737:chemistry* / Q000472:pathogenicity / Q000502:physiology; D002138:Calibration; D002853:Chromatography, Liquid; D005517:Foodborne Diseases / Q000517:prevention & control; D006801:Humans; D057230:Limit of Detection; D055666:Lipopeptides / Q000032:analysis; D008074:Lipoproteins / Q000737:chemistry / Q000302:isolation & purification*; D059625:Liquid-Liquid Extraction / Q000379:methods; D000432:Methanol / Q000737:chemistry; D015394:Molecular Structure; D010456:Peptides, Cyclic / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*; D012015:Reference Standards; D015203:Reproducibility of Results; D012997:Solvents / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D055666:Lipopeptides; D008074:Lipoproteins; D010456:Peptides, Cyclic; D012997:Solvents; C094325:lichenysin A; C009365:surfactin peptide; D000432:Methanol
keywords: Bacillus licheniformis; LC-MS/MS; lichenysin; quantification; validation