title: Effect of soybean oil on oxygen transfer in the production of tetracycline with an airlift bioreactor.
abstract: Corn starch and soybean oil are suitable carbon sources for the production of tetracycline by Streptomyces aureofacience CG-1. However, it could not produce more than 6 g/l of tetracycline even if initial corn starch concentration was increased to more than 100 g/l. It was confirmed by shaking flask experiments that the k(L)a in a mixture of 2% soybean oil in water was four folds compared with that without soybean oil. With the addition of soybean oil to the starch medium in a shaking flask, tetracycline production was significantly improved. By scaling-up to a 5.5-l airlift bioreactor from 500-ml Erlenmeyer flask, more than 10 g/l of tetracycline was produced with the addition of 60 g/l of soybean oil to the medium containing 100 g/l of corn starch. The dissolved oxygen level in the airlift bioreactor containing soybean oil was higher than that without soybean oil. This suggests that soybean oil is not only a suitable carbon source but is also a surface-active agent which may accelerate the oxygen transfer. This may lead to the possibility of the enhanced production of tetracycline at a low cost in airlift bioreactor.
authors.affiliation: Department of Biochemical Engineering, Tianjin University of Light Industry, 300222 Tianjin, China.
authors.forename: S
authors.initials: S
authors.lastname: Jia
authors.forename: G
authors.initials: G
authors.lastname: Chen
authors.forename: P
authors.initials: P
authors.lastname: Kahar
authors.forename: D B
authors.initials: DB
authors.lastname: Choi
authors.forename: M
authors.initials: M
authors.lastname: Okabe