The capacity to create a diffusive chemical concentration gradient in microfluidic systems has the potential to improve the study of microbial processes. These tools allow the evaluation of microbial cell performance under different and controlled conditions. Diffusion-based gradient generators, in particular, have the capacity to maintain spatiotemporally constant gradient concentrations necessary to evaluate cell behavior in a precise environment. This work uses a known microfluidic device capable of generating a diffusive glucose concentration gradient to evaluate for the first time the behavior of Saccharomyces cerevisiae ATCC 7754 inside a microchannel. The cell growth along the microfluidic microchambers was observed and the kinetic parameters determined, with values statistically similar to those of conventional batch cultivation. Monod kinetic parameters could also be determined in the microfluidic device using small substrate concentrations. These results show the potential of this microbioreactor to investigate yeast growth with microliter samples and to evaluate experiments in triplicate performed and in parallel. The diffusive concentration gradient in a microfluidic device allowed the acquisition of results in a more practical way when compared to conventional techniques.

Keywords: Microfluidics; Gradient concentration; Bioprocess monitoring; Microbial growth; Kinetic parameters; Yeast.