Resveratrol production in bioreactor: Assessment of cell physiological states and plasmid segregational stability

Abstract

Resveratrol is a plant secondary metabolite commonly found in peanuts and grapevines with significant health benefits. Recombinant organisms can produce large amounts of resveratrol and, in this work, Escherichia coli BW27784 was used to produce resveratrol in bioreactors while monitoring cell physiology and plasmid stability through flow cytometry and real-time qPCR, respectively. Initially, the influence of culture conditions and precursor addition was evaluated in screening assays and the data gathered was used to perform the bioreactor assays, allowing the production of 160 μg/mL of resveratrol. Cellular physiology and plasmid instability affected the final resveratrol production, with lower viability and plasmid copy numbers associated with lower yields. In sum, this study describes new tools to monitor the bioprocess, evaluating the effect of culture conditions, and its correlation with cell physiology and plasmid segregational stability, in order to define a viable and scalable bioprocess to fulfill the need for larger quantities of resveratrol.

Keywords: Cell physiology; Flow Cytometry; Plasmid stability; Real-time qPCR; Resveratrol.

Fig. 1

Influence of p-coumaric acid concentration (A), optical density (OD₆₀₀) at addition of precursor (B), temperature (C), pH (D) on resveratrol production in the screening assays and maximum production obtained (E), with the level and optical density corresponding to the maximum obtained in each factor, in a 48 h fermentation. The values are presented as mean ± SD of three measurements.