Zifan Wang

The massive amount of water-soluble urea used leads to nutrient loss and environmental pollution in both water and soil. The aim of this study was to develop a novel lignin-based slow-release envelope material that has essential nitrogen and sulfur elements for plants. After the amination reaction with a hydrolysate of yak hair keratin, the coating formulation was obtained by adding different loadings (2, 5, 8, 14 wt%) of aminated lignin (AL) to 5% polyvinyl alcohol (PVA) solution. These formulations were cast into films and characterized for their structure, thermal stability, and mechanical and physicochemical properties. The results showed that the PVA-AL (8%) formulation had good physical and chemical properties in terms of water absorption and mechanical properties, and it showed good degradation in soil with 51% weight loss after 45 days. It is suitable for use as a coating material for fertilizers. Through high-pressure spraying technology, enveloped urea particles with a PVA-AL (8%) solution were obtained, which showed good morphology and slow-release performance. Compared with urea, the highest urea release was only 96.4% after 30 days, conforming to Higuchi model, Ritger–Peppas model, and second-order dynamic model. The continuous nitrogen supply of PVA-AL coated urea to Brassica napus was verified by potting experiments. Therefore, the lignin-based composite can be used as a coating material to produce a new slow-release nitrogen fertilizer for sustainable crop production.

The loose and porous structure and abundant pores of biochar provide conditions for being a suitable fertilizer carrier. Biochar loaded with beneficial microorganisms will greatly promote plant growth and soil improvement. In this work, an environmentally friendly Paenibacillus mucilaginosus loaded biochar-based fertilizer (B@PM) with high nutrient content, good slow-release effect and increased biological activity was prepared. The released mechanism of P-K-Ca from B@PM and the synergistic effect on the soil nutrients and plant growth were also analyzed. The experimental results showed that the release behavior of P, K and Ca from B@PM was diffusive and dissolved, which conforms to the Power function and Parabolic diffusion models, respectively. The potting experiment showed that the root length (30.77%), leaf width (71.67%), and plant height (81.08%) of Chinese cabbage were enhanced after the application of B@PM, and the organic matter, available phosphorus, available potassium, and total calcium in the soil were also substantially enhanced. In addition, the abundance of the Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes in the in the rhizosphere soil was increased, as well as the activities of catalase (82.84%) and alkaline phosphatase (39.64%). The results of RDA analyses showed that B@PM increased the content of the environmental factors, such as OM, URE, EC, TCa, AK, CAT, AP and ALP, thus improving soil quality and plant length.

Background Hydroxyanthraquinones and anthraquinone glucoside derivatives are always considered as the active antibacterial components. Methods Comparison of structure characteristics and antibacterial effect of these compounds was performed by applying quantum chemical calculations, atoms in molecules theory, molecular docking, and dynamics simulation procedure. Density functional theory calculation with B3LYP using 6-31G (d, p) basis set has been used to determine ground state molecular geometries. Results The molecular geometric stability, electrostatic potential, frontier orbital energies, and topological properties were analyzed at the active site. Once glucose ring is introduced into the hydroxyanthraquinone rings, almost all of the positive molecular potentials are distributed among the hydroxyl hydrogen atoms of the glucose rings. In addition, low electron density ρ (r) and positive Laplacian value of the O–H bond of the anthraquinone glucoside are the evidences of the highly polarized and covalently decreased bonding interactions. The anthraquinone glucoside compounds have generally higher intermolecular binding energies than the corresponding aglycones due to the strong interaction between the glucose rings and the surrounding amino acids. Molecular dynamics simulations further explored the stability and dynamic behavior of the anthraquinone compound and protein complexes through RMSD, RMSF, SASA, and Rg. Conclusion The type of carboxyl, hydroxyl, and hydroxymethyl groups on phenyl ring and the substituent glucose rings is important to the interactions with the topoisomerase type II enzyme DNA gyrase B.

The abuse of agricultural antibiotics has led to the emergence of drug-resistant phytopathogens. Rifampicin and streptomycin and streptomycin resistance Pectobacterium carotovorum subsp. carotovorum (PccS1) was obtained from pathological plants in a previous experiment. Rheum tanguticum, derived from the Chinese plateau area, exhibits excellent antibacterial activity against PccS1, yet the action mode has not been fully understood. In present text, the cell wall integrity of the PccS1 was tested by the variation of the cellular proteins, SDS polyacrylamide gel electrophoresis (SDS-PAGE), scanning electron microscopy (SEM) and Fourier transform infrared spectrophotometer (FTIR) characteristics. Label-free quantitative proteomics was further used to identify the DEPs in the pathogen response to treatment with Rheum tanguticum Maxim. ex Balf. extract (abbreviated as RTMBE). Based on the bioinformatics analysis of these different expressed proteins (DEPs), RTMBE mainly inhibited some key protein expressions of beta-Lactam resistance, a two-component system and phosphotransferase system. Most of these membrane proteins were extraordinarily suppressed, which was also consistent with the morphological tests. In addition, from the downregulated flagellar motility related proteins, it was also speculated that RTMBE played an essential antibacterial role by affecting the swimming motility of the cells. The results indicated that Rheum tanguticum can be used to attenuate the virulence of the drug-resistant phytopathogenic bacteria.