Department of Chemical Engineering, Indian Institute of Technology, Hauz Khas, New Delhi, 110016, India.
Appl Microbiol Biotechnol. 2020 Jul;104(13):5773-5785. doi: 10.1007/s00253-020-10652-6. Epub 2020 May 15.
Microaerobic fermentation has been shown to improve lactose transport and recombinant protein production in Escherichia coli. Mechanistic correlation between lactose and dissolved oxygen has been studied and it has been demonstrated that E. coli can switch its genetic machinery upon fluctuations in dissolved oxygen levels and thereby impact lactose transport, resulting in product formation. Continuous induction of lactose in microaerobic fermentation led to a 3.3-fold improvement in product titre of rLTNF oligomer and a 1.8-fold improvement in product titre of rSymlin oligomer as compared with traditional aerobic fermentation. Transcriptome profiling indicated that ribosome synthesis, lactose transport and amino acid synthesis genes were upregulated during microaerobic fermentation. Besides, novel lactose transporter setB was examined and it was observed that lactose uptake rate was 1.4-fold higher in microaerobic fermentation. The results indicate that microaerobic fermentation can offer a superior alternative for industrial production of recombinant therapeutics, industrial enzymes and metabolites in E. coli. KEY POINTS: • Microaerobic fermentation results in significantly improved protein production • Lactose transport, ribosome synthesis and amino acid synthesis are enhanced • Product titre improves by 1.8-3.3-fold.
微需氧发酵已被证明可以提高大肠杆菌中乳糖的转运和重组蛋白的生产。已经研究了乳糖和溶解氧之间的机制相关性，并已经证明大肠杆菌可以根据溶解氧水平的波动来切换其遗传机制，从而影响乳糖的转运，从而导致产物的形成。与传统好氧发酵相比，在微需氧发酵中连续诱导乳糖可使 rLTNF 低聚物的产物滴度提高 3.3 倍，rSymlin 低聚物的产物滴度提高 1.8 倍。转录组分析表明，在微需氧发酵过程中核糖体合成、乳糖转运和氨基酸合成基因被上调。此外，还检查了新型乳糖转运蛋白 setB，并观察到微需氧发酵中乳糖的摄取率提高了 1.4 倍。结果表明，微需氧发酵可为大肠杆菌中重组治疗药物、工业酶和代谢物的工业生产提供更好的选择。关键点：•微需氧发酵可显著提高蛋白质产量•乳糖转运、核糖体合成和氨基酸合成增强•产物滴度提高 1.8-3.3 倍。
