title: Enhanced separation and analysis procedure reveals production of tri-acylated mannosylerythritol lipids by Pseudozyma aphidis.
abstract: Mannosylerythritol lipids (MELs) are one of the most promising biosurfactants because of their high fermentation yields (>100 g l-1) and during the last two decades they have gained a lot of attention due to their interesting self-assembling properties and biological activities. In this study, MELs were produced by fed-batch bioreactor fermentation of rapeseed oil with Pseudozyma aphidis MUCL 27852. This high-level MEL-producing yeast secretes four conventional MEL structures, -A, -B, -C and -D, which differ in their degree of acetylation. During our research, unknown compounds synthesized by P. aphidis were detected by thin-layer chromatography. The unknown compounds were separated by flash chromatography and identified as tri-acylated MELs by high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The third fatty acid chain on the tri-acylated MELs was positioned on the primary alcohol of the erythritol moiety and comprised long-chain acids, mainly oleic and linoleic acid, which are not found in conventional di-acylated MELs. Furthermore, the LC-MS analysis time of conventional MELs was reduced to almost one-third by switching from HPLC-MS/MS to ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Provided optimization of the fermentation yield, P. aphidis could be an interesting novel producer of tri-acylated MELs and, thereby expand the supply and applicability of biosurfactants.
authors.affiliation: Department of Chemistry, Faculty of Science, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium. eliane.goossens@uantwerp.be.|Faculty of Applied Engineering, University of Antwerp, Salesianenlaan 90, 2660, Hoboken, Belgium. eliane.goossens@uantwerp.be.
authors.forename: Eliane
authors.identifier: 0000-0001-6679-2520
authors.initials: E
authors.lastname: Goossens
authors.affiliation: Faculty of Applied Engineering, University of Antwerp, Salesianenlaan 90, 2660, Hoboken, Belgium.
authors.forename: Marc
authors.initials: M
authors.lastname: Wijnants
authors.affiliation: Oleon NV, Assenedestraat 2, 9940, Ertvelde, Belgium.
authors.forename: Dirk
authors.initials: D
authors.lastname: Packet
authors.affiliation: Department of Chemistry, Faculty of Science, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium. filip.lemiere@uantwerp.be.
authors.forename: Filip
authors.initials: F
authors.lastname: Lemière
mesh_terms: D000107:Acetylation; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D005227:Fatty Acids / Q000032:analysis; D005285:Fermentation; D006017:Glycolipids / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D000074262:Rapeseed Oil / Q000378:metabolism; D013501:Surface-Active Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D014587:Ustilaginales / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D006017:Glycolipids; D000074262:Rapeseed Oil; D013501:Surface-Active Agents; C439671:mannosylerythritol lipid
keywords: Flash chromatography; Mannosylerythritol lipids; Pseudozyma aphidis; Tri-acylated MELs; UPLC–MS/MS