Structural characterization and surface-active properties of a new glycolipid biosurfactant, mono-acylated mannosylerythritol lipid, produced from glucose by Pseudozyma antarctica.
Mannosylerythritol lipids (MELs), which are glycolipid biosurfactants produced by Pseudozyma yeasts, show not only excellent interfacial properties but also versatile biochemical actions. In the course of MEL production from glucose as the sole carbon source, P. antarctica was found to produce unknown glycolipids more hydrophilic than conventional "di-acylated MELs," which have two fatty acyl esters on the mannose moiety. Based on a detailed characterization, the most hydrophilic one was identified as 4-O-(3'-O-alka(e)noyl-beta-D: -mannopyranosyl)-D: -erythritol namely, "mono-acylated MEL." The mono-acylated MEL reduced the surface tension of water to 33.8 mN/m at a critical micelle concentration (CMC) of 3.6 x 10(-4) M, and its hydrophilic-lipophilic balance was tentatively calculated to be 12.15. The observed CMC was 100-fold higher than that of the MELs hitherto reported. Interestingly, of the yeast strains of the genus Pseudozyma, only P. antarctica and P. parantarctica gave the mono-acylated MEL from glucose, despite a great diversity of di-acylated MEL producers in the genus. These strains produced MELs including the mono-acylated one at a rate of 20-25%. From these results, the new MEL is likely to have great potential for use in oil-in-water-type emulsifiers and washing detergents because of its higher water solubility compared to conventional MELs and will thus contribute to facilitating a broad range of applications for the environmentally advanced surfactants.
Fukuoka
Tokuma
T
Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5-2, 1-1-1, Higashi, Tsukuba, Ibaraki, 305-8565, Japan.
Morita
Tomotake
T
Konishi
Masaaki
M
Imura
Tomohiro
T
Sakai
Hideki
H
Kitamoto
Dai
D
D000890:Anti-Infective Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D001487:Basidiomycota / Q000378:metabolism*; D001709:Biotechnology / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D005947:Glucose / Q000378:metabolism*; D006017:Glycolipids / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D057927:Hydrophobic and Hydrophilic Interactions; D008826:Microbial Sensitivity Tests; D019906:Nuclear Magnetic Resonance, Biomolecular; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology
D000890:Anti-Infective Agents; D006017:Glycolipids; D013501:Surface-Active Agents; C439671:mannosylerythritol lipid; D005947:Glucose