Bioresour Technol. 2026 Jun 29:135271. doi: 10.1016/j.biortech.2026.135271. Online ahead of print.

ABSTRACT

1-Deoxynojirimycin (1-DNJ) is a potent α-glucosidase inhibitor and a highly promising next-generation hypoglycemic agent, however, the catalytic efficiencies of its critical synthetases GabT1, YktC1 and GutB1 (TYB) are relatively low, which severely limits its large-scale production, and this research aimed to establish a cost-effective microbial cell factory for 1-DNJ production by integrating protein and metabolic engineering. Firstly, the ancestral sequence of aminotransferase GabT1 was reconstructed and engineered, and the optimal double-mutant zxGabT1^DM1 showed a 52.23% elevation of relative activity compared to native GabT1. Adopting the similar strategy, the activities of double mutants YktC1^DM and GutB1^DM were elevated by 126.68% and 54.63%, respectively. When the optimal synthetases (zxGabT1^DM1, YktC1^DM and GutB1^DM) were co-expressed in the strain HD19, the yield of 93.45 mg/L 1-DNJ was obtained, which was 32.81% higher than that of control strain HD18. Then, the engineered MTYB fusion protein was spatially organized by the CipA protein scaffold, and 1-DNJ yield reached 172.53 mg/L. Moreover, endogenous alkaline protease aprE gene was overexpressed to achieve efficient biotransformation of agro-industrial by-product peanut meal (PM), and 2.15 g/L 1-DNJ was acquired using the constructed strain HD29 in a 5 L fermenter, which was the highest 1-DNJ yield reported for a metabolically engineered strain to date. Collectively, this work not only establishes a green and sustainable biotechnological platform for 1-DNJ efficient production, but also opens up a promising avenue for valorizing agro-industrial by-product PM.

PMID:42372983 | DOI:10.1016/j.biortech.2026.135271