title: Analytical characterization of mannosylerythritol lipid biosurfactants produced by biosynthesis based on feedstock sources from the agrofood industry.
abstract: Mannosylerythritol lipids (MELs) are currently one of the most promising biosurfactants because of their multifunctional applications and good biodegradability. Depending on the yeast strain and the feedstock used for the fermentation process, structural variations in the MELs obtained occur. Therefore, MELs produced by Pseudozyma aphidis DSMZ 70725 with a soybean oil feedstock were characterized by chromatography and mass spectrometry (MS). Column chromatography with silica provided fractionation of the different types of MEL. High-performance liquid chromatography combined with MS was employed for the analysis of the MEL fractions and crude mixtures. A characteristic MS pattern for the MELs was obtained and indications of the presence of new MEL homologues, showing the incorporation of longer and more unsaturated fatty acid chains than previously reported, were given. Gas chromatography-MS analysis confirmed the presence of such unsaturated fatty acid chains in the MELs, demonstrating the incorporation of fatty acids with lengths ranging from C(8) to C(14) and with up to two unsaturations per chain. The incorporation of C(16) and C(18) fatty acid chains requires further investigation. MS/MS data allowed the unambiguous identification of the fatty acids present in the MELs. The product ion spectra also revealed the presence of a new isomeric class of MELs, bearing an acetyl group on the erythritol moiety.
authors.affiliation: Department of Industrial Sciences and Technology, Karel de Grote University College, Research Group Industrial Biotechnology, Salesianenlaan 30, 2660 Hoboken, Antwerp, Belgium.
authors.forename: Matthias
authors.initials: M
authors.lastname: Onghena
authors.forename: Tinne
authors.initials: T
authors.lastname: Geens
authors.forename: Eliane
authors.initials: E
authors.lastname: Goossens
authors.forename: Marc
authors.initials: M
authors.lastname: Wijnants
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Pico
authors.forename: Hugo
authors.initials: H
authors.lastname: Neels
authors.forename: Adrian
authors.initials: A
authors.lastname: Covaci
authors.forename: Filip
authors.initials: F
authors.lastname: Lemiere
mesh_terms: D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D005285:Fermentation; D008401:Gas Chromatography-Mass Spectrometry; D006017:Glycolipids / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D013024:Soybean Oil / Q000378:metabolism; D013501:Surface-Active Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D014587:Ustilaginales / Q000737:chemistry / Q000378:metabolism*
chemical_list: D006017:Glycolipids; D013501:Surface-Active Agents; C439671:mannosylerythritol lipid; D013024:Soybean Oil