Skip to content

Author

Zhi-qiang Liu

3 papers indexed here

We haven’t gathered this author’s papers yet. Follow them and we’ll fetch their work.

Not the right person? Other researchers publish under this name.

Jul 2026

Beyond direct pathway engineering: reprogramming Fusarium fujikuroi from a GA3 producer into a GA4+7 factory.

Synthetic biology is emerging as a key approach in chemical synthesis, whose efficiency hinges crucially on the direct engineering of metabolic pathways. In this study, we propose a dual-intervention paradigm to reprogram the industrial fungus Fusarium fujikuroi from a default gibberellic acid (GA3) producer into an exclusive factory for the higher-value gibberellin GA4+7, providing a complementary and orthogonal approach to traditional intra-pathway manipulations. First, by introducing Arabidopsis-derived transporters (Npfs and Sweets), we successfully created a thermodynamic sink that actively depletes intracellular GA4/GA7 pools. With the best candidate protein, Sweet1, the parent strain was converted into an exclusive producer of GA4+7 (with GA3 levels undetectable), a conversion driven by the significantly accelerated dissociation rate (Kdis) for GA7. Concurrently, we uncovered a non-canonical, highly specific regulatory mechanism: overexpression of the Sfp-type 4'-phosphopantetheinyl transferase Ppt1 triggered targeted post-transcriptional silencing of up to 99.9 % of P450-3 mRNA, thereby completely silencing GA3 biosynthesis and again yielding an exclusive producer of GA4+7. Synergistic integration of transporter-driven spatial pulling and Ppt1-mediated gene silencing, coupled with fermentation optimization, propelled the final GA4+7 titer to an unprecedented 3.29 g/L (reaching 0.4 g/L for GA4 and 2.89 g/L for GA7, representing 17.39-, 962.33-, and 125.54-fold increases over the parent strain, respectively). This study achieves indirect metabolic reprogramming not via conventional pathway engineering, but by targeting a membrane transport bottleneck and employing a putative post-transcriptional silencing mechanism.

Hang Xiao, Tao-Xu Lu, Ming-Han-Li-Ming-Han Li et al. · 0 citations
Jul 2026

Active Pocket Engineering of d-Tagatose 4-Epimerase for Improved Catalytic Performance and Efficient Cascade Synthesis of d-Tagatose from d-Glucose.

d-Tagatose is a rare hexose sugar with excellent properties, and its synthesis catalyzed by d-tagatose 4-epimerase (T4E) represents a competitive novel pathway. In this study, EbT4E derived from the Eubacteriales bacterium was screened and systematically characterized. By reshaping the microenvironment of the active pocket, mutant M3(S131D/H410W/T279S) was constructed, which showed a 3.89-fold higher conversion rate compared with the wild-type (WT) enzyme. Kinetic parameter analysis and molecular dynamics (MD) simulations revealed that M3 had enhanced substrate affinity, hydrogen bond network, charge properties, and channel accessibility. Finally, the conversion rates of d-fructose to d-tagatose catalyzed by the purified M3 enzyme and M3 whole-cell catalysts reached 29.46% and 26.2%, respectively. Additionally, the dual-enzyme cascade reaction of M3 with glucose isomerase (GI) TEGI-M-L38M-V137L was constructed, achieving a 13.16% yield of d-tagatose from d-glucose. This study demonstrates that EbT4E-M3 is a promising biocatalyst for d-tagatose production, laying the foundation for its subsequent industrial application.

Yu-Si Zhang, Zhi-Qiang Li, Jia-Hui Chen et al. · 0 citations