title: Biological modification of the fatty acid group in an emulsan by supplementing fatty acids under conditions inhibiting fatty acid biosynthesis.
abstract: When the concentration of the antibiotic cerulenin was increased up to 3.0 mg/l in medium containing ethanol as a carbon source, the specific growth rate of Acinetobacter calcoaceticus and the fatty acid content of the emulsan decreased from 0.179 h(-1) and 13.9% to 0.015 h(-1) and 3.4%, respectively. The emulsifying activity in medium containing cerulenin decreased with increasing cerulenin concentration. In the culture containing 3.0 mg/l cerulenin, fatty acid biosynthesis was inhibited. Various fatty acids were added to this inhibitory culture as a second carbon source to modify the fatty acid group in the emulsan. When an odd-numbered fatty acid was added, the resulting emulsan was found to have other odd-numbered fatty acids that were not present originally. Among the emulsan produced from even-numbered fatty acids, the emulsan produced from myristic acid (C14) contained the greatest amount of the same-numbered fatty acids. When the amount of supplemental myristic acid was increased, the myristic acid content in the emulsan increased, but its emulsifying activity decreased.
authors.affiliation: Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Taejon 305-701, Korea.
authors.forename: P
authors.initials: P
authors.lastname: Kim
authors.forename: D K
authors.initials: DK
authors.lastname: Oh
authors.forename: J K
authors.initials: JK
authors.lastname: Lee
authors.forename: S Y
authors.initials: SY
authors.lastname: Kim
authors.forename: J H
authors.initials: JH
authors.lastname: Kim