Applied Biochemistry and Microbiology最新文献

The extraction of lignin was carried out from corn cobs, pine and aspen sawdust using a deep eutectic solvent choline chloride/oxalic acid (molar ratio 1 : 1). The extracted lignins were characterized by UV-visible and Fourier transform infrared spectroscopy methods. Their antioxidant and UV-protective properties were compared. Lignins from the pine and aspen had a high antioxidant activity towards DPPH^• and ABTS^+• free radicals, while lignin from the corn cobs had the highest adsorption capacity towards the synthetic dye methylene blue (30.8 mg/g). All three lignins demonstrated a high efficiency as an active component of UV-shielding films and can be used in food packaging and cosmetics.

The analysis of a change in the proteome of pea seedling roots under the influence of signaling mediators involved in plant defense reactions was carried out. It was demonstrated that the roots of pea plants specifically responded to the effect of compounds that can be mimetics of signals from the rhizosphere by a change in proteomes. Methyl jasmonate was used as a mimetic of elicitors of necrotrophic pathogens; salicylic acid and nitric oxide (NO) donor, of biotrophic pathogens; azelaic acid and cycloheximide, an antibiotic produced by soil streptomycetes, as transport inducers of systemic immunity. A specificity of the root response was manifested in the fact that only NO donor caused the induction of ferritin and phenylcoumaran benzyl ester reductase Betv6. The induction a large number of enzymes of flavonoid synthesis occurred only under the action of azelaic acid and cycloheximide, and only cycloheximide increased the content of isopentenyl pyrophosphate isomerase, a key enzyme of terpenoid synthesis.

The effect of the composition of inducers on the secretion of proteolytic enzymes of the entomopathogenic micromycete Akanthomyces cf. aculeatus under conditions of submerged cultivation was studied. A preparation of proteolytic enzymes of the micromycete Akanthomyces cf. aculeatus was obtained, fractionated by isoelectrofocusing using the Westerberg method, and characterized. The complex preparation contains a neutral serine protease having homology with a subtilisin-like serine peptidase from the S8 family. A peptidase with collagenolytic and fibrinogenolytic activity was isolated. Its properties were studied, and its glycosylation was analyzed.

The review discusses the enzymatic reduction systems that maintain animal heme-containing globins in a physiologically active state. There are two types of reductases. Specialized systems (two-component: cytochrome-b₅ reductase/cytochrome b₅) provide rapid reduction of hemoglobin (Hb) and myoglobin (Mb), which is important for oxygen transport and storage. The main enzyme, CYB5R3, reduces Hb, Mb, and presumably cytoglobin (Cygb) and neuroglobin (Ngb). CYB5R4 most probably preferentially works with Cygb and Ngb in tissues with low activity of CYB5R3. Reductases with wide specificity, thio-reductase 1 (TXNRD1) and NADPH:cytochrome-P450 reductase (CPR), function as reserve systems. In addition to their role in antioxidant protection and detoxification, they effectively reduce globins (especially Cygb and Ngb), showing the relationship between cell’s redox status and globin functions. All these systems not only support oxygen transport function of globins, but also regulate nitric oxide metabolism, providing vascular tone and protection against hypoxia and oxidative stress. Their dysfunction leads to pathologies, the most severe of which is hereditary methemoglobinemia.

Phthalic acid esters (PAEs) are ubiquitous organic xenobiotics widely distributed in the environment and pose a significant threat to human health, including concerns related to food safety. Among PAEs, di-(2-ethylhexyl) phthalate (DEHP), diisobutyl phthalate (DiBP), and butyl benzyl phthalate (BBP) are most frequently detected in the environment and agricultural products at relatively high concentrations. The presence of these PAEs in agro-industrial ecosystems can substantially affect the composition of soil and plant-associated microbial communities, leading to reduced crop yields and deterioration of agricultural product quality. To address these challenges, bioremediation approaches are commonly employed, including microbial degradation and mycoremediation. In the present study, the intracellular degradation mechanisms of DEHP, DiBP, and BBP by the white-rot fungus Trametes hirsuta LE-BIN 072 were investigated using a proteomic approach. Among the enzymes involved in the degradation of these phthalates, various esterases, alcohol dehydrogenases (ADHs), aldehyde dehydrogenases (ALDHs), aldo-keto reductases of families 7 and 13 (AKR7A and AKR13A), short-chain dehydrogenases/reductases (SDRs), and several other oxidoreductases were identified.

The ubiquity of nitriles today and, according to one hypothesis, their presence as one of the basic substrates during the emergence of life in the early stages of Earth’s history, has led to the emergence of microorganisms producing nitrile-hydrolyzing enzymes among a wide variety of phylogenetic and ecological groups, including extremophilic prokaryotes and a small number of unicellular eukaryotic organisms. This review summarizes information on nitrile-degrading microorganisms isolated from extreme biotopes that differ in origin and type of aggressive environmental conditions. Nitrile-hydrolyzing enzymes, their substrate preferences, whole-cell culture conditions, and optimal environmental parameters for nitrile-hydrolyzing activity are characterized. The main areas of study and application of nitrile-utilizing microorganisms are biotechnological (use as biocatalysts for various chemical processes and the biodegradation of toxic cyanides and nitriles), ecological (clarification of the role of nitriles in the nitrogen cycle), and evolutionary (molecular clock dating). Particular attention is given to the role of nitriles in the natural nitrogen cycle.

The use of the redox indicator resazurin for estimating the intracellular activity of the original derivative of pyrano[3,2-b]indolone Pyr056 with anti-tuberculosis activity in vitro was proposed in the work. The estimation of the number of M. tuberculosis in the cultures of infected macrophage cell line RAW264.7 treated with Pyr056 by counting CFU and by measuring the fluorescence intensity of reduced resazurin demonstrated a high degree of positive correlation (r = 0.982). On the one hand, this result opens up the prospect of further study of the anti-tuberculosis activity of Pyr056, including in vivo experiments; on the other hand, the possibility of using resazurin for rapid and accurate estimation of the efficiency of experimental compounds against various intracellular pathogens, including M. tuberculosis, especially in the case of limited time and resources.

For the first time, studies were conducted to evaluate the susceptibility of bacterial biofilm cells to an antibiotic by using a compact acoustic sensor system based on a lateral electric field resonator. The antibiotic’s activity against the bacteria was indicated by the change in the sensor system’s analytical signal for the antibiotic-exposed biofilm bacteria. The results were confirmed by microbiological culturing and microscopy data. The advantages of this approach include the ability to repeatedly use the sensor system outside the laboratory and obtain results within a short period (10 min).

The emergence of drug resistance in microbial cells is a serious public health problem. Therefore, the development of new alternative antibacterial agents to combat multidrug-resistant bacteria is becoming increasingly important. The rapid development of nanotechnology and nanoparticle synthesis has facilitated the emergence of new strategies for combating microbial cells. Silver nanoparticles, which possess antibacterial activity, are particularly valuable. Nanoparticle synthesis involves various physical and chemical methods using toxic reagents that pollute the environment. Therefore, cost-effective alternative processes for synthesizing nanomaterials using biological systems, biological or “green” nanoparticle synthesis, are being actively developed. Natural biological sources, including fungi, bacteria, plants, animal cells, viruses, and their metabolites, can be used for green nanoparticle synthesis. The use of biological objects to create inorganic nanoparticles is a relatively new area of biotechnology. Green synthesis of noble metal nanoparticles is a vast and growing area of research. This paper presents the basic principles of green synthesis technology for producing silver nanoparticles, as well as the advantages and disadvantages of its application. The potential for using nanoparticles obtained using green synthesis technology as antimicrobial agents is discussed.

To mitigate the increase in Staphylococcus aureus resistance resulting from antibiotic misuse, this study aimed to identify natural and safe antibacterial substances as alternatives to conventional antibiotics for treating S. aureus infections in animal husbandry. An antibacterial protein (APBS) with broad pH and thermal stability was successfully purified from the culture supernatant of Bacillus subtilis FB123 using ammonium sulfate precipitation, Sephacryl S-200 High Resolution gel filtration chromatography, and DEAE Sepharose Fast Flow ion exchange chromatography. APBS exhibited a significant inhibitory effect against S. aureus, producing an inhibition zone diameter up to 16.5 mm. Investigation of its physicochemical properties revealed that APBS displayed optimal antibacterial activity at 30°C and pH 6.0, and retained high activity even after treatment at 121°C and across a broad pH range from 2.0 to 9.0. The molecular weight of APBS was estimated to be approximately 14.8 kDa by SDS-PAGE, and its isoelectric point was determined to be 3.64. Furthermore, this protein demonstrated broad spectrum of antibacterial activity against other Gram-positive bacteria and fungi. Finally, the effects of various proteases, metal ions, and organic solvents on its activity were investigated to assess the potential practical application of APBS. This study indicates that the APBS from B. subtilis FB123 holds promising potential for development as a novel anti-S. aureus agent.