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Synthetic aromatic esters, widely employed in agriculture, food, and chemical industries, have become emerging environmental pollutants due to their strong hydrophobicity and poor bioavailability. This study attempted to address this issue by extracellularly expressing the promiscuous aminopeptidase (Aps) from Pseudomonas aeruginosaGF31 in B. subtilis, achieving an impressive enzyme activity of 13.7 U/mg. Notably, we have demonstrated, for the first time, the Aps-mediated degradation of diverse aromatic esters, including but not limited to pyrethroids, phthalates, and parabens. A biochemical characterization of Aps reveals its esterase properties and a broader spectrum of substrate profiles. The degradation rates of p-nitrobenzene esters (p-NB) with different side chain structures vary under the action of Aps, showing a preference for substrates with relatively longer alkyl side chains. The structure-dependent degradability aligns well with the binding energies between Aps and p-NB. Molecular docking and enzyme–substrate interaction elucidate that hydrogen bonding, hydrophobic interactions, and π–π stacking collectively stabilize the enzyme–substrate conformation, promoting substrate hydrolysis. These findings provide new insights into the enzymatic degradation of aromatic ester pollutants, laying a foundation for the further development and modification of promiscuous enzymes.

The combination of phenolic resin (PF) impregnation-pyrolysis (PIP) and MoSi2-Si-Al alloy activated melting infiltration (AAMI) combination process were used to prepare MoSi2-RSiC composites, in which the RSiC works as a matrix. Influence of infiltrated temperatures on the composition, microstructure, mechanical and electrical properties of the composites were studied by XRD, SEM, mechanical test et. al.. The results showed that an almost fully dense MoSi2-RSiC composite with 3-D interpenetrated network structure was obtained, the compositions of it were mainly SiC, MoSi2 , Mo (Si,Al)2, and small amount of residual Si. With the increase of infiltrated temperatures, the flexural strength of the composites increased first and then decreased, it reached 171.40MPa when infiltrated at 1800°C, which was 107.63% higher than that of RSiC matrix. The fracture properties of the composites exhibited a typical brittle rupture. The composites possessed a volume resistivity of 2.90×10-3 Ω·cm when infiltrated temperature equaled to 1900°C, which was nearly four order of magnitude lower than that of RSiC.