<p>The robust control of biomass and substrate concentrations in a biochemical reactor displaying bifurcation is presented in this study. The system that is being examined is a continuous stirred tank reactor. The system exhibits non-minimum phase features and linked dynamics. The plant’s non-minimum phase characteristics are countered with a compensator. Using quantitative feedback theory, robust controllers and prefilters are developed loop-wise to satisfy the required tracking, sensitivity and stability requirements at the lowest possible loop gain (feedback cost). The purpose of additional feedforward controllers is to reduce cross-coupling. The findings show that, in spite of parametric uncertainties and disruptions, the performance requirements are robustly satisfied. Additionally, the benefits and drawbacks of the suggested control method in comparison with the published studies are discussed.</p>