The production of chiral amines by transaminase-catalyzed amination of ketones is an important application of biocatalysis in synthetic chemistry. It requires transaminases that show high enantioselectivity in asymmetric conversion of the ketone precursors. A robust derivative of ω-transaminase from Pseudomonasjessenii (PjTA-R6) that naturally acts on aliphatic substrates was constructed previously by our group. Here, we explore the catalytic potential of this thermostable enzyme for the synthesis of optically pure aliphatic amines and compare it to the well-studied transaminases from Vibrio fluvialis (VfTA) and Chromobacterium violaceum (CvTA). The product yields indicated improved performance of PjTA-R6 over the other transaminases, and in most cases, the optical purity of the produced amine was above 99% enantiomeric excess (e.e.). Structural analysis revealed that the substrate binding poses were influenced and restricted by the switching arginine and that this accounted for differences in substrate specificities. Rosetta docking calculations with external aldimine structures showed a correlation between docking scores and synthetic yields. The results show that PjTA-R6 is a promising biocatalyst for the asymmetric synthesis of aliphatic amines with a product spectrum that can be explained by its structural features.

Nowadays, global warming is becoming more and more serious, while CO 2 capture technologies have emerged endlessly, with methods of solid-phase CO 2 capture for physical adsorption and liquidphase CO 2 capture for chemical absorption. Biochar has been widely used to achieve CO 2 sequestration and emission reduction as a result of its wide range of precursor sources, strong adsorption, and rich surface functional groups. It reviews the existing post-combustion CO 2 capture solutions, focusing on the analysis of CO 2 capture technologies based on liquid-phase ammonia/monoethanolamine and solid-phase carbonbased materials. The former (liquid phase) is with limitation of capture efficiency as a result of strong volatility and thermal degradation, while the latter (solid phase) is accompanied by limited CO 2 /N 2 selectivity. The realization of synergy between the two would "learn from each other's strengths" to improve the CO 2 adsorption ability. The review puts forward the concept of "biochar-functionalized crosslinking synergistic ammonia CO 2 capture technology", which not only broadens the idea of multi-level utilization of biochar, significantly improving the liquid-phase (ammonia) CO 2 capture efficiency, but also has practical significance for the utilization of biomass waste and reduction of CO 2 emissions.

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As a chemical absorption method, the new ammonia carbon capture technology can capture CO2. Adding ethanol to ammonia can reduce the escape of ammonia to a certain extent and increase the absorption rate of CO2. The dissolution and crystallization of ethanol can realize the crystallization of ammonium bicarbonate and generate solid products. The induction of the crystallization process is influenced by many parameters, such as solution temperature, supersaturation, and solvating precipitant content. The basic nucleation theory is related to the critical size of nucleation. Accurate measurement of the induction period and investigating relevant factors can help to assess the nucleation kinetics. The effects of solubilizer content, temperature, and magnetic field on the induction period of the crystallization process of ammonium bicarbonate in the ethanol–H2O binary solvent mixture and determining the growth mechanism of the crystal surface by solid–liquid surface tension and surface entropy factor are investigated. The results indicate that under the same conditions of mixed solution temperature, the crystallization induction period becomes significantly longer, the solid–liquid surface tension increases, and the nucleation barrier becomes more significant and less likely to form nuclei as the content of solvating precipitants in the components increases. At the same solubilizer content, there is an inverse relationship between the solution temperature and the induction period, and the solid–liquid surface tension decreases. The magnetic field can significantly reduce the induction period of the solvate crystallization process. This gap tends to decrease with an increase in supersaturation; the shortening reduces from 96.9% to 84.0%. This decreasing trend becomes more and more evident with the rise of solvent content in the solution. The variation of surface entropy factor under the present experimental conditions ranges from 0.752 to 1.499. The growth mode of ammonium bicarbonate in the ethanol–H2O binary solvent mixture can be judged by the surface entropy factor as continuous growth.