Background The critical issue in the competitiveness between bioengineering and chemical engineering is the products titer and the volume productivity. The most direct and effective approach usually employs high-density biocatalyst, while the weakened mass transfer and evoked foam problem accompany ultrahigh-density biocatalyst loading and substrate/product titer. In high-density obligate aerobic bioconversion, oxygen as electron acceptor is a speed-limiting step in bioprocesses, but sufficient oxygen supply will lead to the foaming which results in a significant reduction in oxygen utilization and the use of additional defoamers. In this study, we designed a novel sealed-oxygen supply (SOS) biotechnology to resolve the formidable barrier of oxygen transferring rate (OTR), for bio-based fuels and chemical production process. Results Based on systemic analysis of whole-cell catalysis in Gluconobacter oxydans, a novel sealed-oxygen supply technology was smartly designed and experimentally performed for biocatalytic oxidation of alcohols, sugars and so on. By a simple operation skill of automatic online supply of oxygen in a sealed stirring tank bioreactor of SOS, OTR barrier and foaming problem was resolved with great ease. We finally obtained ultrahigh-titer products of xylonic acid (XA), 3-hydroxypropionic acid (3-HPA), and erythrulose at 588.4 g/L, 69.4 g/L, and 364.7 g/L, respectively. Moreover, the volume productivity of three chemical products was improved by 150-250% compared with normal biotechnology. This SOS technology provides a promising approach to promote bioengineering competitiveness and advantages over chemical engineering. Conclusion SOS technology was demonstrated as an economic and universally applicable approach to bio-based fuels and chemicals production by whole-cell catalysis. The novel technology greatly promotes the competitiveness of bioengineering for chemical engineering, and provides a promising platform for the green and environmental use of biofuels.

中文翻译：

---

通过密封供氧生物技术 (SOS) 解决超高效价生物转化/生物催化中的氧转移率 (OTR) 的巨大障碍。

背景 生物工程与化学工程之间竞争力的关键问题是产品效价和产量。最直接和有效的方法通常采用高密度生物催化剂，而超高密度生物催化剂负载和底物/产物滴度伴随着传质减弱和诱发泡沫问题。在高密度专性好氧生物转化中，氧气作为电子受体是生物过程中的一个限速步骤，但充足的氧气供应会导致发泡，从而导致氧气利用率显着降低，并使用额外的消泡剂。在这项研究中，我们设计了一种新型密封供氧 (SOS) 生物技术，以解决生物基燃料和化学生产过程中氧气转移率 (OTR) 的巨大障碍。结果在系统分析氧化葡糖杆菌全细胞催化作用的基础上，巧妙地设计并实验了一种新型的密封供氧技术，用于醇类、糖类等的生物催化氧化。通过SOS密闭搅拌罐生物反应器自动在线供氧的简单操作技巧，OTR阻隔和起泡问题轻松解决。我们最终获得了分别为 588.4 g/L、69.4 g/L 和 364.7 g/L 的木糖酸 (XA)、3-羟基丙酸 (3-HPA) 和赤藓酮糖的超高效价产物。此外，三种化工产品的产量比普通生物技术提高了150-250%。这种 SOS 技术为提高生物工程的竞争力和优于化学工程的优势提供了一种有前途的方法。结论 SOS 技术被证明是一种经济且普遍适用的全细胞催化生物基燃料和化学品生产方法。该新技术极大地提升了生物工程对化学工程的竞争力，为生物燃料的绿色环保利用提供了广阔的平台。