Identification of Ustilago cynodontis as a new producer of glycolipid biosurfactants, mannosylerythritol lipids, based on ribosomal DNA sequences.
Mannosylerythritol lipids (MELs) are one of the most promising glycolipid biosurfactants known because of their multifunctionality and biocompatibility. The search for novel producers of MELs was undertaken based on the analysis of ribosomal DNA sequences on basidiomycetous yeasts. The bermuda grass smut fungus Ustilago cynodontis NBRC 7530, which taxonomically relates to Pseudozyma shanxiensis known as a MEL-C producer, was found to accumulate glycolipids in the cultured medium. Under a shake flask culture with soybean oil, the amount of the glycolipids was 1.4 g/L for 7 days at 25 degrees C. As a result of the structural characterization, the main glycolipids was identified as 4-O-[(4'-O-acetyl-3'-O-alka(e)noyl-2'-O-butanoyl)-beta-D-mannopyranosyl]-D-erythritol, and the major fatty acids were C(14) and C(16) ones. The glycolipid was highly hydrophilic MEL-C, and very similar to those produced by P. shanxiensis. The fungi of the genus Ustilago are thus likely to be potential producers of MELs as well as the yeasts of the genus Pseudozyma.
Morita
Tomotake
T
Research Institute for Innovation in Sustainable Chemistry, National institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan.
Konishi
Masaaki
M
Fukuoka
Tokuma
T
Imura
Tomohiro
T
Kitamoto
Dai
D
D001483:Base Sequence; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics*; D006017:Glycolipids / Q000096:biosynthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods / Q000592:standards; D008968:Molecular Conformation; D010802:Phylogeny; D012015:Reference Standards; D013237:Stereoisomerism; D013501:Surface-Active Agents / Q000737:chemistry*; D014588:Ustilago / Q000235:genetics* / Q000378:metabolism
D004275:DNA, Ribosomal; D006017:Glycolipids; D013501:Surface-Active Agents; C439671:mannosylerythritol lipid