title: Production of a novel glycolipid biosurfactant, mannosylmannitol lipid, by Pseudozyma parantarctica and its interfacial properties.
abstract: The development of a novel glycolipid biosurfactant was undertaken using the high-level producers of mannosylerythritol lipids (MELs) such as Pseudozyma parantarctica, Pseudozyma antarctica, and Pseudozyma rugulosa. Besides the conventional MELs (MEL-A, MEL-B, and MEL-C), these yeasts produced an unknown glycolipid when they were cultivated in a medium containing 4% (w/v) olive oil and 4% (w/w) mannitol as the carbon source. The unknown glycolipid extracted from the culture medium of P. parantarctica JCM 11752(T) displayed the spot with lower mobility than that of known MELs on TLC and provided mainly two peaks identical to mannose and mannitol on high-performance liquid chromatography after acid hydrolysis. Based on structural analysis by (1)H and (13)C nuclear magnetic resonance, the novel glycolipid was composed of mannose and mannitol as the hydrophilic sugar moiety and was identified as mannosylmannitol lipid (MML). Of the strains tested, P. parantarctica JCM 11752(T) gave the best yield of MML (18.2 g/L), which comprised approximately 35% of all glycolipids produced. We further investigated the interfacial properties of the MML, considering the unique hydrophilic structure. The observed critical micelle concentration (CMC) and the surface tension at CMC of the MML were 2.6 x 10(-6) M and 24.2 mN/m, respectively. In addition, on a water-penetration scan, the MML efficiently formed not only the lamella phase (Lalpha) but also the myelins at a wide range of concentrations, indicating its excellent self-assembling properties and high hydrophilicity. The present glycolipid should thus facilitate the application of biosurfactants as new functional materials.
authors.affiliation: Research Institute for Innovation in Sustainable Chemistry, Tsukuba Central, Higashi, Ibaraki, Japan.
authors.forename: Tomotake
authors.initials: T
authors.lastname: Morita
authors.forename: Tokuma
authors.initials: T
authors.lastname: Fukuoka
authors.forename: Masaaki
authors.initials: M
authors.lastname: Konishi
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Imura
authors.forename: Shuhei
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Masaru
authors.initials: M
authors.lastname: Kitagawa
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sogabe
authors.forename: Dai
authors.initials: D
authors.lastname: Kitamoto
mesh_terms: D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D003470:Culture Media / Q000737:chemistry; D006017:Glycolipids / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology*; D057927:Hydrophobic and Hydrophilic Interactions; D009682:Magnetic Resonance Spectroscopy; D008353:Mannitol / Q000378:metabolism; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology*; D014587:Ustilaginales / Q000254:growth & development / Q000378:metabolism*
chemical_list: D003470:Culture Media; D006017:Glycolipids; D013501:Surface-Active Agents; D008353:Mannitol