Influence of Epichloë bromicola endophytic fungi on secondary metabolites following alkali tolerance improvement in host, Hordeum bogdanii

Purpose: The aim of this study was to investigate how endophytic fungi affect secondary metabolites of H. bogdanii under alkaline stress at different concentrations. It is currently unclear whether the mechanism via which endophytic fungi improve the alkali tolerance of Hordeum bogdanii affects secondary metabolites. Unveiling this knowledge is crucial for understanding the tolerance mechanism of H. bogdanii to alkaline stress. Methods: Endophyte-infected (E+) and endophyte-free (E-) individuals of H. bogdanii were used as materials in this study. Vermiculite was used for plant cultivation and was carried out in the laboratory. After mixed alkali stress treatment, the roots, stems, and leaves of the plants were collected to measure the indicators related to secondary metabolites. Results: The results showed that endophytic fungi significantly increased the contents of phosphorus, polyphenols, and alkaloids, and the activities of polyphenol oxidase and acid phosphatase, and significantly reduced flavonoid content. The content of polyphenols and alkaloids in stems, polyphenol oxidase activity in stems and leaves, and acid phosphatase activity in leaves were significantly affected. In general, endophytic fungi improved the alkali resistance of H. bogdanii by improving the related indicators of secondary metabolites. Conclusions: The findings of this study may aid in amplifying the alkali resistance mechanism of endophytic fungi to H. bogdanii as well as provide insights into improving the alkali resistance of other plants.

Beading Mechanism and Performance of Porous Steel Slag Microbead Abrasive

The use of the gas-quenching process for preparing porous bead slag abrasive was investigated in this paper. An X-ray diffractometer, field emission scanning electron microscope, mercury intrusion porosimetry, and stereo microscope were used to analyze the microbead forming mechanism, pore structure, acid–alkali resistance, and polishing properties of porous steel slag microbead abrasives. Results show that the porous steel slag abrasives present a mono-disperse spherical shape with a hard shell and the porosity is 42.36%. The thermodynamic fractal model indicates that the fractal dimension of the abrasive is 2.226, which shows its simple pore structure. The sample has better chemical stability in the polishing fluid than in water, acid, and alkali solution. Therefore, aluminum and copper alloys are used as substrates for polishing tests. The results indicate that the abrasives could effectively improve the quality of the workpiece surface and the polishing efficiency for aluminum alloy was higher than that for copper alloy.

Multifunctional alkalophilic α-amylase with diverse raw seaweed degrading activities

Uncultured microbes are an important resource for the discovery of novel enzymes. In this study, an amylase gene (amy2587) that codes a protein with 587 amino acids (Amy2587) was obtained from the metagenomic library of macroalgae-associated bacteria. Recombinant Amy2587 was expressed in Escherichia coli BL21 (DE3) and was found to simultaneously possess α-amylase, agarase, carrageenase, cellulase, and alginate lyase activities. Moreover, recombinant Amy2587 showed high thermostability and alkali resistance which are important characteristics for industrial application. To investigate the multifunctional mechanism of Amy2587, three motifs (functional domains) in the Amy2587 sequence were deleted to generate three truncated Amy2587 variants. The results showed that, even though these functional domains affected the multiple substrates degrading activity of Amy2587, they did not wholly explain its multifunctional characteristics. To apply the multifunctional activity of Amy2587, three seaweed substrates (Grateloupia filicina, Chondrus ocellatus, and Scagassum) were digested using Amy2587. After 2 h, 6 h, and 24 h of digestion, 121.2 ± 4 µg/ml, 134.8 ± 6 µg/ml, and 70.3 ± 3.5 µg/ml of reducing sugars were released, respectively. These results show that Amy2587 directly and effectively degraded three kinds of raw seaweeds. This finding provides a theoretical basis for one-step enzymatic digestion of raw seaweeds to obtain seaweed oligosaccharides.

Recycling of Blast Furnace Slag and Fluorite Tailings into Diopside-Based Glass-Ceramics with Various Nucleating Agents’ Addition

Diopside-based glass-ceramics are successfully produced by recycling blast furnace slag and fluorite tailing with the addition of supplementary elements such as TiO2, Fe2O3 and Cr2O3 as nucleation agents, using a conventional melting method. The effects of various nucleating agents on the phase components and structure of the prepared glass-ceramics were evaluated by a differential scanning calorimeter, X-ray diffraction and scanning electron microscope–energy disperse spectrometer methods to determine the optimal dosage of nucleating agents. The results show that, in the preparation of diopside-based glass-ceramics, the suitable percentages of blast furnace and fluorite tailing are 55% and 45%, and the recommended composite nucleating agents consist of 1.5% Cr2O3, 2% TiO2 and 3% Fe2O3. Heat treatment was conducted at a nucleation temperature of 720 °C and a crystallization temperature of 920 °C, and the nucleation and crystallization durations were 1.0 h and 1.5 h, respectively. Under the abovementioned parameters, the obtained diopside-based glass-ceramics displayed a Vickers hardness of 7.12 GPa, density of 2.95 g·cm−3, water absorption of 0.02%, acid resistance of 0.23% and alkali resistance of 0.02%.

Solution to the problems of complex use of mineral raw materials

The increasing pace of construction in areas in eastern Russia is leading to an increased demand for building materials. To meet this demand, local raw materials, including basalt, are widely used. In this article, we have shown the possibility of complex use of basalts in the production of various types of products. Using low-temperature plasma, basalt fibre with good physical and chemical characteristics was obtained. It possesses high heat-resistance (up to 700°C) and alkali resistance, and is stable in aqueous medium. Using mechanical activation method composite binding materials were obtained. Technological parameters of their production are determined. It is shown that the binding materials with optimal composition have a compressive strength higher than the strength of the control sample by 18%. The integrated use of mineral raw materials allows us to solve the issues of energy efficiency, resource conservation and environmental safety in the development of mineral deposits and the production of new types of products.

Study on Finishing of Polychlorotrifluoroethylene Resin by Magnetic Abrasive Finishing Process with Renewable Abrasive Particles

Polychlorotrifluoroethylene material is used in industry as a material with excellent insulation, impact resistance and acid and alkali resistance. In this study, we used a magnetic abrasive finishing process with renewable abrasive particles to finish the surface of the polychlorotrifluoroethylene resin plate. Magnetic Abrasive Finishing (MAF) process is a technology that uses flexible magnetic brushes to improve the surface quality of materials. The performance of the magnetic brush is a key factor in surface finishing. In conventional MAF finishing, the number of abrasive particles in the magnetic brush is limited, and the position of the abrasive particles is relatively fixed, which will cause the cutting edge of the abrasive particles to gradually become dull and the finishing efficiency gradually decreases. This paper research the characteristics of the MAF process with renewable abrasive particles. This MAF process has a circulating system that uses a conveyor belt to renew abrasive particles. We use the polychlorotrifluoroethylene resin plate as the experimental processing object to conducted finishing experiment. And the surface roughness of the polychlorotrifluoroethylene resin plate is improved from 315 nm to 32 nm through this process.

Dye Decoloring Peroxidase Structure, Catalytic Properties and Applications: Current Advancement and Futurity

Dye decoloring peroxidases (DyPs) were named after their high efficiency to decolorize and degrade a wide range of dyes. DyPs are a type of heme peroxidase and are quite different from known heme peroxidases in terms of amino acid sequences, protein structure, catalytic residues, and physical and chemical properties. DyPs oxidize polycyclic dyes and phenolic compounds. Thus they find high application potentials in dealing with environmental problems. The structure and catalytic characteristics of DyPs of different families from the amino acid sequence, protein structure, and enzymatic properties, and analyzes the high-efficiency degradation ability of some DyPs in dye and lignin degradation, which vary greatly among DyPs classes. In addition, application prospects of DyPs in biomedicine and other fields are also discussed briefly. At the same time, the research strategy based on genetic engineering and synthetic biology in improving the stability and catalytic activity of DyPs are summarized along with the important industrial applications of DyPs and associated challenges. Moreover, according to the current research findings, bringing DyPs to the industrial level may require improving the catalytic efficiency of DyP, increasing production, and enhancing alkali resistance and toxicity.

Properties of Microfibers of Various Compositions as a Component of Cellular Composites

The paper presents studies on the properties of various types of micro-reinforcing fibers to assess their role and effectiveness in the structure formation of the cellular composite. Based on the data on the weight loss after exposure in a model medium of cement, analysis of the alkali resistance of fibers of five different types – basalt fiber, heat-treated basalt fiber, polymer fiber and glass fibers from two different manufacturers – was carried out. It is shown that the fibers have a sufficiently high durability in the medium of hardening cement, which is expressed by a relatively insignificant weight loss of the original fiber after exposure in a model medium for 28 days in ambient conditions. The weight loss for some fibers sharply increases when hardening conditions are changed to hydrothermal ones. The images of fibers exposed in a model medium of cement, obtained using scanning microscopy, were also analyzed, and the character of distribution of acidic and basic adsorption sites on the surface of fibers depending on the type was assessed. Based on the analysis of the obtained data, we can talk about a high number of active sites on the surface of basalt and glass fibers, which ensures the formation of crystalline new formations on them and makes it possible to predict their high adhesion to the cement matrix.