This part explores the evolving transition from traditional fed-batch fermentation to continuous flow systems in microbial bioprocessing. It highlights a fundamental shift in control philosophy, moving from time-dependent trajectories to the maintenance of steady-state regimes through advanced variables like dilution and retention. The source examines foundational tools such as chemostats alongside modern hybrid architectures like perfusion and multi-stage reactors that aim to maximize industrial productivity. Furthermore, it integrates these methods into a unified framework of dynamic optimal control, where computational models and real-time analytics balance economic goals with biological constraints. Ultimately, the text presents continuous processing not as a replacement for fed-batch methods, but as a sophisticated extension of metabolic control logic. Adopting these systems requires overcoming challenges in genetic stability and operational complexity through a strategic, staged implementation.