Yang Mu,Fuyin Zhang,Ning Li,Shanshan Pi,Ang Li,Qing Hong,Jian He,Jiguo Qiu,Jiandong Jiang
Dipicolinic acid (DPA) is a widely distributed pyridine derivative containing two carboxylate groups. However, the catabolism of DPA mediated by microorganisms are rarely reported. Alcaligenes faecalis strain JQ135, previously isolated in our lab, was able to degrade various pyridine derivatives, including nicotinic acid (NA). In this study, it was found that strain JQ135 could utilize DPA as the sole carbon and nitrogen source for growth and degrade 1.8 mM (300 mg/L) DPA to a non-detectable level within 12 h. The catabolism of DPA by strain JQ135 extracted two intermediates, i.e., 3-hydroxy-2,6-dipicolinic acid and 4-imino-pent-2-enedioic acid. Moreover, deletion of the key genes essential for NA catabolism (such as moaCDEBmoeA and maiA ) did not affect DPA catabolism, indicating that the maleamate pathway and molybdenum cofactor are not involved in the DPA catabolism by strain JQ135. This study will provide insights into the bacterial catabolism of DPA.
Xinliang Wang,Zhiwei Wang,Changqing Xia,Zhengshen Bao,Dehong Xu,Yinhai Ma,Shixing Wang,Weili Li
In this work, functional organic ligands are incorporated into the structurally stable metal–organic framework (UiO-66-SPA) to regulate the electrostatic potential and coordination positions of its inner and outer surfaces. The gold extraction efficiency of functionalized MOFs from acidic gold-containing wastewater is 2.65 times that of non-functionalized UiO-66-(SH) 2 . In this way, efficient recovery of Au(III) in complex trace Au(III) wastewater is achieved. After multiple regeneration cycles, UiO-66-SPA still maintains 99% of its adsorption capacity. Through characterization techniques such as X-ray photoelectron spectroscopy (XPS), density functional theory (DFT) calculations, kinetics, and thermodynamics, it is confirmed that the adsorption of Au(III) by UiO-66-SPA involves the synergistic effect of chelation coordination. This work provides a way to enhance adsorption for the post-modification of MOFs. The experiment of recovering Au(III) from industrial simulated wastewater improves the experimental data for the application of this material in Au(III) recovery. The research in this article is of great significance for MOFs materials in environmental protection, sustainable development of non-renewable resources, and green development of Au(III) resources.
危险品化学品经营许可证（带存储）