Anionic oxyl radical formed on CrVI-oxo anchored on the defect site of the UiO-66 node facilitates methane to methanol conversion.

The direct conversion of methane to methanol has attracted increasing interest due to abundant and low-cost natural gas resources. Herein, by anchoring Cr-oxo/-oxyhydroxides on UiO-66 metal-organic frameworks, we demonstrate that reactive anionic oxyl radicals can be formed by controlling the coordination environment based on the results of density functional theory calculations. The anionic oxyl radicals produced at the completely oxidized CrVI site acted as the active species for facile methane activation.

Enhancing tylosin production by combinatorial overexpression of efflux, SAM biosynthesis, and regulatory genes in hyperproducing strain.

Tylosin is a 16-membered macrolide antibiotic widely used in veterinary medicine to control infections caused by Gram-positive pathogens and mycoplasmas. To improve the fermentation titer of tylosin in the hyperproducing strain TL01, we sequenced its whole genome and identified the biosynthetic gene cluster therein. Overexpression of the tylosin efflux gene , the luster-ituated -adenosyl methionine (SAM) synthetase gene , the SAM biosynthetic genes -, or the pathway-specific activator gene enhanced tylosin production by 18%, 12%, 11%, and 11% in the respective engineered strains TLPH08-2, TLPH09, TLPH10, and TLPH12.

Key to the Chinese species of the subgenus Sphodromimus Casale, 1984 (Carabidae, Chlaeniini, ) with descriptions of two new species.

The subgenus Sphodromimus Casale, 1984 in China has been studied, revealing two new species: Chlaenius (Sphodromimus) caperatus from Hunan Province and Chlaenius (Sphodromimus) yinggelingensis from Hainan Province. A new replacement name is proposed for C. (Sphodromimus) wrasei (Kirschenhofer, 2003) [nec Chlaenius (Lithochlaenius) wrasei Kirschenhofer, 1997]: Chlaenius (Sphodromimus) davidi.

Coupled oxygen desorption and structural reconstruction accompanying reduction of copper oxide.

Understanding structural transformation and phase transition accompanying reactions in a solid as a catalyst or oxygen carrier is important to the design and optimization of many catalytic or chemical looping reaction processes. Herein, we combined density functional theory calculation with the stochastic surface walking global optimization approach to track the structural transformation accompanying the reduction of CuO upon releasing oxygen. We then used machine learning (ML) methods to correlate the structural properties of CuO with varying x.

Correlation between the Properties of Surface Lattice Oxygen on NiO and Its Reactivity and Selectivity towards the Oxidative Dehydrogenation of Propane.

Modified NiO catalysts with controllable vacancies and dopants are promising for alkene production from oxidative dehydrogenation (ODH) of light alkanes, and a molecular understanding of the modification on elementary reaction steps would facilitate the design of highly efficient catalysts and catalytic processes. In this study, density functional theory (DFT) calculations was used to map out the complete reaction pathways of propane ODH on the NiO (100) surfaces with different modifiers. The results demonstrated that the presence of vacancies (O and Ni) and dopants (Li and Al) alters the electrophilicity of surface oxygen species, which in turn affects the reactivity towards C-H bond activation and the overall catalytic activity and selectivity.

Candida glycerinogenes Strains Overexpressing Transcription Factors have Improved Furfural Tolerance in Ethanol Production from Non-detoxified Cellulose Hydrolysate.

Cellulose is one of the main raw materials for production of green ethanol, but the presence of the growth inhibitor furfural in non-detoxified lignocellulosic hydrolysates often seriously affects their utilization. In a previous study, we obtained strains of Candida glycerinogenes that were tolerant to furfural, but at concentrations above 2.5 g L there was a significant increase in the growth lag phase.