Heterologous fermentation of a diterpene fromAlternaria brassisicola.
A variety of different applications render terpenes and terpenoids attractive research targets. A promising but so far insufficiently explored family of terpenoids are the fusicoccanes that comprise a characteristic 5-8-5 fused tricyclic ring system. Besides herbicidal effects, these compounds also show apoptotic and anti-tumour effects on mammalian cells. The access to fusicoccanes from natural sources is scarce. Recently, we introduced a metabolically engineeredSaccharomyces cerevisiaestrain to enable the heterologous fermentation of the shared fusicoccane-diterpenoid precursor, fusicocca-2,10(14)-diene. Here, we show experiments towards the identification of bottlenecks in this process. The suppression of biosynthetic by-products via medium optimisation was found to be an important aspect. In addition, the fermentation process seems to be improved under oxygen limitation conditions. Under fed-batch conditions, the fermentation yield was reproducibly increased to approximately 20 mg/L. Furthermore, the impact of the properties of the terpene synthase on the fermentation yield is discussed, and the preliminary studies on the engineering of this key enzyme are presented.
Department for Chemistry and Biochemistry, Ruhr University Bochum , 44780 Bochum , Germany.
Julia
J
Arens
Department of Biochemical and Chemical Engineering, TU Dortmund University , 44227 Dortmund , Germany.
Dominik
D
Bergs
Department of Chemistry and Chemical Biology, TU Dortmund University , 44221 Dortmund , Germany.
Mirja
M
Mewes
Department of Biochemical and Chemical Engineering, TU Dortmund University , 44227 Dortmund , Germany.
Juliane
J
Merz
Department of Biochemical and Chemical Engineering, TU Dortmund University , 44227 Dortmund , Germany.
Gerhard
G
Schembecker
Department for Chemistry and Biochemistry, Ruhr University Bochum , 44780 Bochum , Germany.
Frank
F
Schulz
anti-tumour; directed evolution; enzyme engineering; heterologous fermentation; metabolic engineering; terpenes