Resveratrol is an important antioxidant that confers several beneficial effects on human health. 4-coumarate coenzyme A ligase (4CL) and resveratrol synthase (RS) are key rate-limiting enzymes in the biosynthetic pathway of resveratrol. Using gene fusion technology, the fusion gene, 4CL::RS, was constructed by the 4CL gene from Arabidopsis thaliana and RS gene from Arachis hypogaea. DNAMAN analysis showed that the fusion gene encoded a 964-amino acid protein with an approximate weight of 104.7 kDa and a pI of 5.63. A prokaryotic expression vector containing Nco-I and EcoR-I restriction sites, pET-30a/4CL::RS, was identified by liquid culture bacterial PCR, enzyme digestion, and sequencing, and then used in the induction of expression. Subsequently, a biosynthetic pathway of resveratrol was constructed in Escherichia coli BL21(DE3) that harbored pET-30a/4CL::RS. The recombinant strains were induced to express the fusion protein at 28 °C for 8 h. After bacterial cells were disrupted by hypothermic ultrasonication, the 4CL::RS fusion protein was thoroughly separated from tags using Ni-NTA affinity chromatography, and then detected by SDS-PAGE analysis. When the recombinant strains expressed the fusion protein, the precursor, p-coumaric acid, was converted to resveratrol. In the present study, the final concentration of resveratrol derived from 1 mM p-coumaric acid was 80.524 mg/L, with a 35.28 % (mol/mol) conversion yield.

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In this work, we introduced a method to prepare porous polymer particles with controllable surface textures by combining the strategies of emulsion interfacial instabilities and phase separation. The oil phase of the emulsion containing the polymer, a cosurfactant, and a nonvolatile oil, which is a nonsolvent for the polymer, is dissolved into a volatile good solvent. With the evaporation of the good solvent, interfacial instability was triggered because of the increasing concentrations of both the cosurfactant and polymer; meanwhile, phase separation between the polymer and the nonsolvent occurred. Completely removing the good solvent resulted in the formation of porous polymer particles with surface roughness. Varying the concentration of the cosurfactant and nonsolvent allowed the surface textures and internal pore structures to be tuned. Porous polymer particles with surface roughness could have potential applications in the fields of enzyme carriers, isolation and purification, superhydrophobic coatings, drug delivery, and so forth.

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