S04 - Session O6 - Optimization of fed-batch culture for polyphenol production from Theobroma cacao cell culture

Authors: María Isabel Restrepo Muriel *, Lucía Atehortúa, Luisa Fernanda Rojas Hoyos

Polyphenols, the secondary metabolites produced by cacao seeds ( Theobroma cacao ) are known for their antioxidant effects and benefits to human health. The increasing demand to find alternative methods to produce them at a commercial scale have focused on cell cultures and more specifically the batch culture. However, a fed-batch culture offers a better approach to produce polyphenols efficiently. To date no research has been published on the evaluation of fed-batch for polyphenol production in T. cacao cell cultures. The aim of this study was to evaluate the effect of fed-batch in a stirred tank bioreactor, to improve cell growth and polyphenol production. A batch culture was performed in a 7.5 L-stirred tank bioreactor to obtain the kinetics of cocoa cell growth, polyphenol production and nutrient consumption. The fed-batch culture was designed to supply those nutrients at specific times of culture. The feeding mediums were composed of macronutrients (M1), micronutrients (M2) and a combination of both (M3). The feeding times were on days 7th, 10th and 14th. The results evidenced a significant improvement in the overall culture productivity. The highest cell growth and polyphenol production were obtained with M2 medium on day 7th. The volumetric productivity was 1.01 gL-1d-1 and polyphenol production was 19,07 mgGAE.g-1. These results support the evidence that micronutrients are essential for macronutrients assimilation and are early consumed by cells. On the other hand, polyphenol production was significantly increased by fed- batch culture when compared to batch culture and cocoa beans of the same variety of study. The current study represents a novel investigation in Theobroma cacao cell cultures at a laboratory scale. In consequence the fed-batch culture allowed us to develop a process that can be scaled-up to a plant pilot and later to an industrial scale.