Unfavorable cell heterogeneity is a frequent risk during bioprocess scale-up and characterized by rising frequencies of low-producing cells. Low-producing cells emerge by both non-genetic and genetic variation and will enrich due to their higher specific growth rate during the extended number of cell divisions of large-scale bioproduction. Here, we discuss recent strategies for synthetic stabilization of fermentation populations and argue for their application to make cell factory designs that better suit industrial needs. Genotype-directed strategies leverage DNA-sequencing data to inform strain design. Self-selecting phenotype-directed strategies couple high production with cell proliferation, either by redirected metabolic pathways or synthetic product biosensing to enrich for high-performing cell variants. Evaluating production stability early in new cell factory projects will guide heterogeneity-reducing design choices. As good initial metrics, we propose production half-life from standardized serial-passage stability screens and production load, quantified as production-associated percent-wise growth rate reduction. Incorporating more stable genetic designs will greatly increase scalability of future cell factories through sustaining a high-production phenotype and enabling stable long-term production.

不利的细胞异质性是生物工艺放大过程中的常见风险，其特征是低产细胞的频率上升。低产细胞通过非遗传变异和遗传变异出现，并且由于在大规模生物生产的大量细胞分裂过程中较高的比生长速率而富集。在这里，我们讨论了用于发酵种群合成稳定化的最新策略，并争论了它们在使细胞工厂设计更适合工业需求方面的应用。基因型指导策略利用DNA测序数据来指导菌株设计。自我选择的表型指导策略通过重定向的代谢途径或合成产物生物传感将高产量与细胞增殖结合起来，从而丰富了高性能细胞变异体。在新的电池工厂项目中尽早评估生产稳定性将指导减少异质性的设计选择。作为良好的初始指标，我们建议使用标准化的连续通道稳定性筛选和生产负荷来量化生产半衰期，将其量化为与生产相关的百分比增长率降低。整合更稳定的遗传设计将通过维持高产量表型并实现稳定的长期生产，大大提高未来细胞工厂的可扩展性。