title: Biosurfactant-producing yeast isolated from Calyptogena soyoae (deep-sea cold-seep clam) in the deep sea.
abstract: We describe a detailed structure determination of biosurfactant produced by Pseudozyma hubeiensis SY62, which was newly isolated from Calyptogena soyoae (deep-sea cold-seep clam, Shirouri-gai) at 1156 m in Sagami bay. P. hubeiensis SY62 was taxonomically slightly different from the P. hubeiensis type strain, which produces biosurfactants. Glycolipid production by the strain was also slightly different from those of previously reported strains. BS productivity was estimated to be around 30 g/l from the weight of the crude extract. At least five different spots of glycolipid biosurfactants (BSs) were detected by TLC. Results of nuclear magnetic resonance spectroscopies indicated the major product, namely MEL-C (4-O-[4'-O-acetyl-2',3'-di-O-alka(e)noil-beta-d-mannopyranosyl]-d-erythritol), as a promising BS. By further structural determination, the major fatty acids of MEL-C were estimated to be saturated C(6), C(10), and C(12) acids, which were shorter than those of previously reported MEL-C. Furthermore, (1)H-NMR spectra implied the presence of C(2) acids as acyl groups. According to surface tension determination, the novel MEL-C showed larger critical micelle concentration (1.1x10(-5) M) than conventional MEL-C which bound C(10) and C(12) acids (9.1x10(-6) M). From these results, shorter fatty acids would confer hydrophilicity onto the novel MEL-C.
authors.affiliation: Institute of Biogeosciences, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15, Natsushima-cho, Yokosuka 237-0061, Japan. konishi-masaaki@jamstec.go.jp
authors.forename: Masaaki
authors.initials: M
authors.lastname: Konishi
authors.forename: Tokuma
authors.initials: T
authors.lastname: Fukuoka
authors.forename: Takahiko
authors.initials: T
authors.lastname: Nagahama
authors.forename: Tomotake
authors.initials: T
authors.lastname: Morita
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Imura
authors.forename: Dai
authors.initials: D
authors.lastname: Kitamoto
authors.forename: Yuji
authors.initials: Y
authors.lastname: Hatada
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000382:microbiology*; D009792:Oceans and Seas; D013045:Species Specificity; D013501:Surface-Active Agents / Q000737:chemistry* / Q000378:metabolism*; D014587:Ustilaginales / Q000145:classification* / Q000302:isolation & purification / Q000378:metabolism*; D014871:Water Microbiology
chemical_list: D013501:Surface-Active Agents