Design-for-scale: Engineering strategies for robust microbial chassis to ensure good performance in industrial application.

What does microbial robustness mean in the context of industrial bioprocesses, and which cellular design principles are required to maintain strain performance from laboratory to industrial scale? This review addresses these questions by presenting an integrated systems metabolic engineering perspective on microbial chassis design. Robust production hosts must maintain viability, metabolic function, production capacity, and population stability throughout the entire process trajectory, including the seed train, biomass formation, production, product accumulation, and late-stage stress exposure. The relevant engineering target is therefore not an isolated gene or pathway, but the coordinated cellular system as a whole. Genome architecture, expression control, stress regulation, metabolic flux distribution, membrane physiology, product export, and population stability must be aligned with the intended process and evaluated under dynamic, process-relevant conditions. Accordingly, robustness engineering should begin with the industrial objective in mind while remaining centered on the microbial host.