title: Enhancement of epsilon-polylysine production by Streptomyces albulus strain 410 using pH control.
abstract: The enhancement of epsilon-poly-l-lysine (epsilon-PL) production by Streptomyces albulus strain no. 410 (S410) by means of a pH control strategy was investigated. S140 cells produce epsilon-PL at a high concentration if the culture pH remains at about 4.0; however, if it shifts to higher than 4.0, the accumulated epsilon-PL is depolymerized. We therefore suggest a pH control strategy for cell growth and epsilon-PL production aimed at increasing the amount of epsilon-PL produced. The cultivation was divided into two control phases. In phase I, cell growth was accelerated by maintaining the pH at higher than 5.0; in phase II, epsilon-PL production was increased by maintaining the pH at about 4.0. To avoid an increase in the pH during phase II as a result of glucose depletion, the glucose concentration was kept at around 10 g/l by glucose feeding. This control strategy enhanced the production of epsilon-PL to 48.3 g/l from 5.7 g/l in the case of batch culture.
authors.affiliation: United Graduate School of Agricultural Science, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
authors.forename: P
authors.initials: P
authors.lastname: Kahar
authors.forename: T
authors.initials: T
authors.lastname: Iwata
authors.forename: J
authors.initials: J
authors.lastname: Hiraki
authors.forename: E Y
authors.initials: EY
authors.lastname: Park
authors.forename: M
authors.initials: M
authors.lastname: Okabe