Bioreactor development with immobilized Saccharomyces cerevisiae for brewing: physiology and mathematical modeling

Abstract

Cell immobilization is their physical restriction in a certain region of space through physical and/or chemical methods and, commonly, this technology consists of a solid support containing cell biomass. In beer fermentation, yeast immobilization was widely explored during the 1970s-1990s, with the expectation that the brewing industry would undergo a revolution with a significant increase in productivity and continuous operation. Some industrial applications were developed, but in general sensory profiles required by the quality standard were not achieved. Many operational challenges have arisen and physiological changes in immobilized yeasts have been widely reported. Currently, however, with the rise of the craft beer market and demand for different styles and sensory profiles, yeast immobilization in beer production has gained space again. This is because the physiological changes inherent to immobilization methods can now be explored and not necessarily avoided. Therefore, this project aims to manufacture a benchtop fixed/fluidized bed bioreactor for beer fermentation with immobilized yeasts, in which batch fermentations will be conducted to evaluate the kinetics and physiological state of an Ale strain (Saccharomyces cerevisiae) and with cell reuse. From experimental data, the optimization and mathematical modeling of the system will be carried out, as well as the economic evaluation for a possible scaling up in the future. (AU)