Engineering Escherichia coli for d‑Allulose Production from d‑Fructose by Fermentation

• Published in: Journal of agricultural and food chemistry 2021-11, Vol.69 (45), p.13578-13585
• Main Authors: Guo, Qiang, Zheng, Ling-Jie, Luo, Xuan, Gao, Xin-Quan, Liu, Chen-Yang, Deng, Li, Fan, Li-Hai, Zheng, Hui-Dong
• Format: Article
• Language: English
• Subjects: Biotechnology and Biological Transformations
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/acs.jafc.1c05200

d-Allulose is considered an ideal alternative to sucrose and has shown tremendous application potential in many fields. Recently, most efforts on production of d-allulose have focused on in vitro enzyme-catalyzed epimerization of cheap hexoses. Here, we proposed an approach to efficiently produce d-allulose through fermentation using metabolically engineered Escherichia coli JM109 (DE3), in which a SecY (ΔP) channel and a d-allulose 3-epimerase (DPEase) were co-expressed, ensuring that d-fructose could be transported in its nonphosphorylated form and then converted into d-allulose by cells. Further deletion of fruA, manXYZ, mak, galE, and fruK and the use of Ni2+ in a medium limited the carbon flux flowing into the byproduct-generating pathways and the Embden–Meyerhof–Parnas (EMP) pathway, achieving a ≈ 0.95 g/g yield of d-allulose on d-fructose using E. coli (DPEase, SecY [ΔP], ΔFruA, ΔManXYZ, ΔMak, ΔGalE, ΔFruK) and 8 μM Ni2+. In fed-batch fermentation, the titer of d-allulose reached ≈23.3 g/L.