title: Characterization of new biosurfactant produced by Klebsiella sp. Y6-1 isolated from waste soybean oil.
abstract: To obtain predominant bacteria degrading crude oil, we isolated some bacteria from waste soybean oil. Isolated bacterial strain had a marked tributyrin (C4:0) degrading activity as developed clear zone around the colony after incubation for 24h at 37 degrees C. It was identified as Klebsiella sp. Y6-1 by analysis of 16S rRNA gene. Crude biosurfactant was extracted from the culture supernatant of Klebsiella sp. Y6-1 by organic solvent (methanol:chloroform:1-butanol) after vacuum freeze drying and the extracted biosurfactant was purified by silica gel column chromatography. When the purified biosurfactant dropped, it formed degrading zone on crude oil plate. When a constituent element of the purified biosurfactant was analyzed by TLC and SDS-PAGE, it was composed of peptides and lipid. The emulsification activity and stability of biosurfactant was measured by using hydrocarbons and crude oil. The emulsification activity and stability of the biosurfactant showed better than the chemically synthesized surfactant. It reduced the surface tension of water from 72 to 32 mN/m at a concentration of 40 mg/l.
authors.affiliation: Department of Biotechnology, Faculty of Natural Resources and Life Science, Dong-A University, Busan 604-714, Republic of Korea.
authors.forename: Sang-Cheol
authors.initials: SC
authors.lastname: Lee
authors.forename: Seung-Jin
authors.initials: SJ
authors.lastname: Lee
authors.forename: Sun-Hee
authors.initials: SH
authors.lastname: Kim
authors.forename: In-Hye
authors.initials: IH
authors.lastname: Park
authors.forename: Yong-Seok
authors.initials: YS
authors.lastname: Lee
authors.forename: Soo-Yeol
authors.initials: SY
authors.lastname: Chung
authors.forename: Yong-Lark
authors.initials: YL
authors.lastname: Choi
mesh_terms: D004591:Electrophoresis, Polyacrylamide Gel; D004655:Emulsions; D005516:Food Microbiology; D007709:Klebsiella / Q000302:isolation & purification / Q000378:metabolism*; D013024:Soybean Oil; D013501:Surface-Active Agents / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D004655:Emulsions; D013501:Surface-Active Agents; D013024:Soybean Oil