title: Production of different types of mannosylerythritol lipids as biosurfactants by the newly isolated yeast strains belonging to the genus Pseudozyma.
abstract: Mannosylerythritol lipids (MEL), which are abundantly secreted by yeasts, are one of the most promising biosurfactants known. To obtain various types of MEL and to attain a broad range of applications for them, screening of novel producers was undertaken. Thirteen strains of yeasts were successfully isolated as potential MEL producers; they showed high production yields of MEL of around 20 g l(-1) from 40 g l(-1) of soybean oil. Based on the taxonomical study, all the strains were classified to be the genus Pseudozyma. It is interesting to note that they were categorized into three groups according to their production patterns of MEL. The first group, which included 11 strains taxonomically closely related to high-level MEL producers such as Pseudozyma antarctica and Pseudozyma aphidis, mainly produced 4-O-[(4',6'-di-O-acetyl-2',3'-di-O-alkanoyl)-beta-D-mannopyranosyl]-meso-erythritol (MEL-A) together with 4-O-[(6'-mono-O-acetyl-2',3'-di-O-alkanoyl)-beta-D-mannopyranosyl]-meso-erythritol (MEL-B) and 4-O-[(4'-mono-O-acetyl-2',3'-di-O-alkanoyl)-beta-D-mannopyranosyl]-meso-erythritol (MEL-C) as the minor components. The second group of one strain, which was related to Pseudozyma tsukubaensis, predominantly produced MEL-B. The third group of one strain, which was closely related to Pseudozyma hubeiensis, mainly produced MEL-C; this is the first observation of the efficient production of MEL-C from soybean oil. Moreover, the major fatty acids of the obtained MEL-C were C(6), C(12), and C(16) acids, and were considerably different from those of the other MEL hitherto reported. The biosynthetic manner for MEL is thus likely to significantly vary among the Pseudozyma strains; the newly isolated strains would enable us to attain a large-scale production of MEL and to obtain various types of MEL with different hydrophobic structures.
authors.affiliation: Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, 305-8565, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Konishi
authors.forename: Tomotake
authors.initials: T
authors.lastname: Morita
authors.forename: Tokuma
authors.initials: T
authors.lastname: Fukuoka
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Imura
authors.forename: Koji
authors.initials: K
authors.lastname: Kakugawa
authors.forename: Dai
authors.initials: D
authors.lastname: Kitamoto
mesh_terms: D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D006017:Glycolipids / Q000378:metabolism*; D015394:Molecular Structure; D010802:Phylogeny; D012340:RNA, Ribosomal, 5.8S / Q000235:genetics; D013024:Soybean Oil / Q000378:metabolism; D013501:Surface-Active Agents / Q000378:metabolism*; D014587:Ustilaginales / Q000145:classification / Q000235:genetics / Q000378:metabolism*
chemical_list: D021903:DNA, Ribosomal Spacer; D006017:Glycolipids; D012340:RNA, Ribosomal, 5.8S; D013501:Surface-Active Agents; C439671:mannosylerythritol lipid; D013024:Soybean Oil