Producing recombinant proteins in transgenic plant cell suspension cultures in bioreactors provides controllability, reproducibility, scalability, and low‐cost production, although low yields remain the major challenge. The studies on scaling‐up to pilot‐scale bioreactors, especially in conventional stainless‐steel stirred tank bioreactors (STB), to produce recombinant proteins in plant cell suspension cultures are very limited. In this study, we scaled‐up the production of rice recombinant butyrylcholinesterase (rrBChE), a complex hydrolase enzyme that can be used to prophylactically and therapeutically treat against organophosphorus nerve agents and pesticide exposure, from metabolically regulated transgenic rice cell suspension cultures in a 40‐L pilot‐scale STB. Employing cyclical operation together with a simplified‐process operation (controlling gas sparging rate rather than dissolved oxygen and allowing natural sugar depletion) identified in lab‐scale (5 L) bioreactor studies, we found a consistent maximum total active rrBChE production level of 46–58 µg/g fresh weight in four cycles over 82 days of semicontinuous operation. Additionally, maintaining the overall volumetric oxygen mass transfer coefficient (k_La) in the pilot‐scale STB to be equivalent to the lab‐scale STB improves the maximum total active rrBChE production level and the maximum volumetric productivity to 85 µg/g fresh weight and 387 µg L⁻¹ day⁻¹, respectively, which are comparable to the lab‐scale culture. Here, we demonstrate pilot‐scale bioreactor performance using a metabolically regulated transgenic rice cell culture for long‐term, reproducible, and sustained production of rrBChE.

中文翻译：

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在中试规模的生物反应器中从转基因水稻细胞悬浮培养物中生产重组丁酰胆碱酯酶

在生物反应器中的转基因植物细胞悬浮培养物中生产重组蛋白提供了可控性、可重复性、可扩展性和低成本生产，尽管低产量仍然是主要挑战。关于扩大到中试规模的生物反应器，特别是在传统的不锈钢搅拌罐生物反应器 (STB) 中以在植物细胞悬浮培养中生产重组蛋白的研究非常有限。在这项研究中，我们在 40 -L 中试规模机顶盒。在实验室规模 (5 L) 生物反应器研究中确定的循环操作和简化的过程操作（控制气体喷射速率而不是溶解氧并允许天然糖消耗），我们发现一致的最大总活性 rrBChE 生产水平为 46–在 82 天的半连续操作中，四个循环中的鲜重为 58 µg/g。此外，保持总体积氧传质系数（k_L a) 在中试规模的 STB 中，与实验室规模的 STB 相当，将最大总活性 rrBChE 生产水平和最大体积生产率分别提高到 85 µg/g 鲜重和 387 µg L ^-1 天^-1，这与实验室规模的培养相当。在这里，我们展示了使用代谢调节的转基因水稻细胞培养物的中试规模生物反应器性能，以实现 rrBChE 的长期、可重复和持续的生产。