Applied Biochemistry and Microbiology最新文献

SARS-CoV-2 utilizes host cell RNA-binding proteins (RBPs) to carry out many steps of the infectious cycle. At the same time, a number of human RBPs are involved in antiviral immunity. During circulation in the human population, mutations that appeared in the SARS-CoV-2 genome could alter the interaction between cellular RBPs and the virus. Here, we have analyzed the genomes of various SARS-CoV-2 strains, including the Alpha, Delta and Omicron variants, and proposed a model of interactions between RBPs and SARS-CoV-2 RNA. It turned out that, despite the generally accepted opinion about the importance of the RBP‒virus interaction, since the onset of the COVID-19 pandemic there has been a gradual decrease in the affinity of RBPs for SARS-CoV-2 RNA.

The effect of a preparation containing magnesium and phosphorus compounds on the composition of the resulting effluent and biogas productivity of litter-free chicken manure during its anaerobic monofermentation was studied. It was found that the introduction of this preparation into the bioreactor helps to decrease the pH of the medium, bringing it closer to the standard (7.0–7.5). The best result in biogas productivity among the options using different amounts of the preparation was obtained when it was introduced at a dose of 13.33 g/L of the bioreactor contents. The specific biogas yield in this case was 175.23 ± 5.69 L/g of organic matter (1.51% higher than in the control), and the specific methane yield was 68.38 ± 0.45 L/g (15.50% lower than in the control); however, the difference with the control option was insignificant, indicating the absence of a significant effect of this dose on the indicators of productivity. At the same time, the use of the preparation contributes to an increase in the concentrations of magnesium and total phosphorus in the effluent (by 1.20–1.27 and 1.21–1.27 times, respectively) and a decrease in the content of total nitrogen (by 1.45–1.71 times). In this case, magnesium and phosphorus are concentrated in the solid fraction, and nitrogen is concentrated in the liquid fraction, which is important when using the separated effluent as a fertilizer; an exception is the option with the use of the preparation at a dose of 13.33 g/L; here the content of total phosphorus was higher in the liquid fraction. In the tested doses (53.32, 26.66, and 13.33 g/L of the bioreactor contents), the preparation does not provoke the appearance of struvite crystals, which is favorable when operating the most common vertical bioreactors.

Large-scale screening of the pectinolytic activity of Saccharomyces cerevisiae strains isolated from different types of wines, grape berries, fermenting must, fruit and berry juices, natural sources, and industrial waste from different regions of the world was carried out. Of the 305 strains studied, the majority (249) did not produce active endopolygalacturonase. According to the results obtained, the ability to hydrolyze pectin is generally not characteristic of the species S. cerevisiae. Regardless of the source and site of isolation, S. cerevisiae strains have a single pectinase gene PGU1, usually located on the X chromosome. Other chromosomal sites of PGU1 genes, chromosomes VII/XV and IX, were found only in four strains isolated from fermented palm sap in Malaysia and wine strain I-411 (Transcarpathia, Ukraine). Ten strains of S. cerevisiae with the highest pectinolytic activity were selected, which are of interest for further molecular genetic studies and breeding work with wine yeasts.

The culturing systems of cells in three-dimensional space have become central to the study of interactions between different cell lines. These technologies have become crucial tools in modern cell biology research and have found practical application by eliminating limitations inherent to monolayer cultures and achieving more accurate reproduction of cellular functions. The use of three-dimensional (3D) cell models not only reduces the labor and cost of research but also decreases the amount of work involving laboratory animals. However, a universal method for 3D culturing that combines simultaneously high efficiency and good reproducibility, and at the same time does not require high costs has not yet been developed. In this regard, the search for new alternative strategies aimed at improving the technology of 3D cell culturing continues. This review presents data of Russian and foreign scientific publications on methods for creating 3D cell systems and analyzes their advantages and disadvantages. The necessity of modification of existing methods and development of new ones for 3D cell culturing is discussed.

Intranasal preparations containing double-stranded RNA (dsRNA) and interferon-α2b (IFN-α2b) or IFN-γ as a part of the molecular constructs were more resistant to enzymatic degradation than as individual components. The antiviral activity of dsRNA in mouse fibroblast L929 cells infected with murine encephalomyocarditis virus (EMCV) was increased when IFN was introduced into the construct compared with that for the dsRNA substance alone. An increase in the anti-EMCV activity of the drug was observed with increasing IFN content of the construct. A dose-dependent increase in antiviral activity of IFN incorporated in the molecular constructs was shown against EMCV-infected human embryonic lung cells L-68. The data obtained confirm the prospects for the development of new drugs, the delivery system of which includes IFN and dsRNA, for intranasal administration as prophylactic and therapeutic agents against influenza and other acute respiratory viral infections.

Recombinant proteins for medical use obtained by genetic engineering technology have become an integral part of the pharmacopoeia of various countries. To obtain such proteins, the Chinese hamster ovary (CHO) cell culture is widely used in modern biotechnology due to its high proliferation rate and ease of cultivation. Here, the process of scaling up the production of Bevacizumab, a recombinant humanized monoclonal antibody (mAb) of the IgG1 subclass that selectively binds to and neutralizes the functional activity of the human vascular endothelial growth factor (VEGF), was studied. The process was scaled up in bioreactors with a volume of 10 to 2000 L. First, optimal conditions for culturing СНO cells in the 10-, 200-, 500-, and 2000-liter bioreactors were selected. After that, the production of Bevacizumab was analyzed. The developed process allowed us to obtain the target protein with a yield of 1.4‒2.3 mg/mL of the culture liquid. During scaling, an industrial technological process was developed, the qualitative and quantitative characteristics of which are not inferior to laboratory ones.

Evaluation of sperm-specific gene expression is a potential resource for diagnostics of impaired spermiogenesis, cryoresistance, and the fertility of these germ cells. These are important indicators of sperm quality, which should be taken into account when selecting breeding bulls for collecting semen intended for cryopreservation. Here, a correlation analysis of the expression levels of the AQP7, STK35, IFT27, and PRM1 genes with sperm quality indicators in native and decryopreserved sperm of Holstein bulls was carried out. We found a highly reliable positive correlation between the expression of AQP7, ITF27, and PRM1 with a number of spermatozoa viability indicators and a negative one with indicators characterizing the loss of their functionality. The results obtained can be used for developing transcriptional biomarkers of sperm quality in breeding bulls based on the parameters of cryotolerance and the fertilizing potential of spermatozoa.