Effect of perfluorodecalin as an oxygen carrier on actinorhodin production by Streptomyces coelicolor A3(2)

Abstract

Perfluorodecalin, a perfluorocarbon (PFC), was used in this investigation as a dissolved oxygen carrier in the media of Streptomyces coelicolor cultures. The effects of different concentrations of PFC, PFC emulsified with pluronic F-68 and pluronic alone were investigated in the shake-flask cultures using both defined and complex media. In the defined medium with PFC alone, the maximum biomass and actinorhodin concentrations and the volumetric substrate consumption rates increased with increasing PFC concentration. They decreased dramatically, however, when the PFC concentration exceeded 50% (v/v). Emulsifying the PFC with pluronic F-68 resulted in a significant increase in antibiotic concentration while growth was unaffected. The inclusion of more than 4 g/l pluronic alone in the fermentation medium inhibited the growth. In the complex medium with 40% (v/v) PFC, although the final antibiotic concentration was unaffected, the onset of actinorhodin accumulation was 2 days earlier than that in the control. It was demonstrated that PFC and emulsified PFC did not have any deleterious effects on S. coelicolor cultures.