Liquid Nutrient Research Articles

A revolutionary temporary immersion bioreactor method for commercialscale Musa sp. (Tanduk and Berangan) multiplication

Large-scale clonal banana production is required to supply current industry demand. Conventional tissue culture technique needs to be improvised to overcome the high-cost manufacturing and laborious work involved. Therefore, this study aimed to develop an efficient protocol in clonal banana production by using temporary immersion bioreactor (TIB) technology which uses intermittent immersion in liquid nutrients. This study evaluated the optimum protocol pathway for efficient Musa acuminata cv. Berangan and Musa paradisiaca cv. Tanduk propagation with the application of TIB system. M. acuminata and M. paradisiaca optimum initiation medium were developed in MS (Murashige and Skoog) media supplemented with 3 mg/L 6-Benzylaminopurine (BAP) and 0.2 mg/L Thiamine and 0.3 mg/L Thidiazuron (TDZ) respectively. The optimum proliferation medium in TIB developed in MS media supplemented with 3 mg/L BAP for both varieties. The highest number of shoots was achieved in TIB with 20 initial plantlets and a 15-minute immersion with a 6-hour gap along with a 14-day incubation period. Micropropagation of Musa sp. in Temporary Immersion Bioreactor System (RITA ®) has successfully shown significant growth as compared to MS media agar-conventional technique with reduced phenolic content released in both varieties. In conclusion, the production of Musa acuminata cv Berangan and Musa paradisiaca cv. Tanduk by using a temporary immersion bioreactor (TIB) system has huge potential to improve the scale production output with lower-cost plantlets

Structure and characterization of an extracellular polysaccharide from Paenibacillus polymyxa 88A.

Levan-type polysaccharides, produced by various organisms, are nontoxic, biocompatible, and biodegradable polymers with a wide range of biological activities. They have high potential for use in medicine, cosmetology, and industry. A large amount of levan (41.1 g L-1) was recovered by ethanol precipitation from a liquid nutrient medium of Paenibacillus polymyxa 88A that contained 15 % w/v sucrose as a carbon source. The levan was fractionated by gel-permeation and anion-exchange chromatography and was analyzed by DRIFT and NMR spectroscopy. It was found that levan was represented by slightly branched chains composed of β-(2→6)-Fruf residues. The average molecular mass of the levan was about 1.9 MDa. When shear stress was applied at different temperatures, aqueous levan solutions showed pseudoplastic behavior. As found by SEM, a freeze-dried powdered levan sample had a microporous structure. The levan had excellent emulsifying activity toward sunflower oil, forming an emulsion with long-term stability. Analysis of the antioxidant activity of the levan showed a higher, dose-dependent activity toward ABTS, as compared with that toward DPPH. Finally, the bioactivity of the levan was examined by MTT assay by using human cervical carcinoma (HeLa) cells.

Effective combinations of silver nanoparticles and antimicrobial peptides against antibiotic-resistant bacteria

BACKGROUND: The problem of constantly growing resistance of microorganisms to the antibiotics used forces scientists to constantly search for new antimicrobial agents. AIM: To study the antimicrobial activity and toxicity of silver nanoparticles and antimicrobial peptides with a β-hairpin structure, and to characterize their combined antimicrobial action. MATERIALS AND METHODS: The antimicrobial activity of silver nanoparticles and antimicrobial peptides against antibiotic-resistant bacteria was assessed by serial dilutions in a liquid nutrient medium, and the combined antimicrobial activity – by serial dilutions according to the “checkerboard” method. The toxicity of the substances to human cells was determined using a hemolytic test. RESULTS: The studied silver nanoparticles have pronounced antimicrobial activity and low toxicity to human erythrocytes. Silver nanoparticles containing acetylcysteine are more active against gram-negative bacteria than against gram-positive ones. Synergism of the antibacterial action was detected with the combined use of silver nanoparticles stabilized with sodium oleate and protegrin-1. A synergistic antimicrobial effect was also noted for combinations of silver nanoparticles containing acetylcysteine with protegrin-1, ricaecilin and shuchin-4. CONCLUSIONS: Effective combinations of silver nanoparticles and antimicrobial peptides have been identified that act synergistically against antibiotic-resistant bacterial strains, i.e. they multiply the effect of each other. These combinations can be used as prototypes for the development of antibacterial drugs.

Directed modification of characteristics of syntetyc analogue of proline-rich peptide ChBac3.4 through dendrimerisation

BACKGROUND: According to the World Health Organization, microbial resistance to antibiotics is one of the most serious threats to human health, food safety and economic development. Antimicrobial peptides of animal origin, to which resistance is difficult to develop, appear to be a promising option to overcome this problem. To solve one of the problems in the practical use of peptides — their rapid degradation in blood plasma — dendrimerization of linear analogues of already existing antimicrobial peptides can be used. This work shows that dendrimers of shortened analogue of the natural proline-rich peptide ChBac3.4 are superior in antimicrobial activity to the original peptide and are much more stable in blood serum. At the same time, as the original peptide, branched analogues do not have hemolytic activity. AIM: The aim of this study is to develop new structural analogues of a peptide that have improved stability in blood serum while maintaining high antimicrobial activity. To achieve this, we intend to create dendrimeric (branched) molecules by synthesizing peptides using solid-phase methods. MATERIALS AND METHODS: We will investigate the antimicrobial properties of the peptides using the method of serial dilutions in a liquid nutrient medium against both Gram-positive and Gram-negative bacteria. We will also assess the stability of the peptides by culturing them in the presence of human blood serum. RESULTS: After making modifications to the original peptide, we expect to see a significant increase in its antimicrobial activity against all strains tested. Additionally, we anticipate that the resistance of these peptides will increase many times over. CONCLUSIONS: Overall, our findings suggest that dendrimerization can effectively improve the properties of proline-rich peptides, making them more suitable for use in medical applications.

Effects of combined action of proline-rich peptides of human saliva with antimicrobial proteins

BACKGROUND: The substances that make up mixed saliva exhibit activity against bacteria, viruses and fungi. Among them are various cationic antimicrobial peptides: alpha- and beta-defensins, cathelicidins, histatins, but their concentration is relatively low. On the other hand, saliva widely contains a fraction of proline-rich proteins and products of their proteolysis — peptides, the functions of which currently remain poorly studied and unclear. The study of the antimicrobial activity of proline-rich proteins, in particular, when they act together with antimicrobial peptides, and the deciphering of the molecular and cellular basis for the implementation of the protective functions of proline-rich peptides is an urgent task in medicine and biology. The data obtained will help to understand the mechanisms of anti-infective protection of the oral cavity with the participation of the innate immune system, and in the future will allow the creation of drugs based on proline-rich proteins in humans and animals. AIM: Study of the individual antibacterial action of proline-rich salivary proteins, their combined action with the antimicrobial proteins lactoferrin and lysozyme, as well as with one of the most significant endogenous protective peptides — cathelicidin LL-37 on the formation of bacterial biofilms. MATERIALS AND METHODS: Human lactoferrin and egg lysozyme were used in the work. The minimum inhibitory concentrations of peptides against gram-negative and gram-positive bacteria were estimated using serial dilutions in a liquid nutrient medium. Using serial dilutions using the “chessboard” method, it was shown that proline-rich proteins can increase the antibacterial activity of innate immunity peptides present in the oral cavity. The ability of combinations of cationic proline-rich peptides with cathelicidin LL-37 to prevent the formation of bacterial biofilms was studied. RESULTS: In the presence of proline-rich peptides, the antimicrobial activity of some antimicrobial peptides and proteins present in saliva against planktonic bacteria increases. The combined action of proline-rich proteins with LL-37 increases the inhibition of bacterial biofilm formation. CONCLUSIONS: As a result of the study, it was shown that the analyzed cationic proline-rich peptides of human saliva exhibit anti-inflammatory effects, which suggests their significant role in the regulation of inflammatory processes in the oral cavity, as well as their participation in recovery processes.

РАЗРАБОТКА ЭКСПЕРИМЕНТАЛЬНОЙ ЛЕКАРСТВЕННОЙ ФОРМЫ ДЛЯ МЕСТНОГО ПРИМЕНЕНИЯ С ПРОТИВОГРИБКОВЫМ ДЕЙСТВИЕМ

Currently, mycoses are one of the urgent health problems. According to WHO, up to 1/3 of the world's population suffers from fungal pathologies. Currently, fungal infections are becoming increasingly difficult to treat, which is associated both with the identification of new species of fungi that were previously considered non-pathogenic, and with the development of resistance of pathogens to available medicines. The problem of mycoses is becoming more urgent due to the variety of pathways of transmission of pathogens and their high resistance in the external environment, changes in the immune response of the human body. Therefore, it is so important to expand the range and constantly improve the compositions and forms of antifungal agents. The substance of the silver salt pyrazole-3-carboxamide (SSP) synthesized in PGFA showed antifungal activity, which allowed it to be included in the experimental mild dosage form. The purpose of this study is to develop an experimental mild dosage form based on the silver salt of pyrazole–3-carboxamide for topical use in candidiasis dermatomycosis and to evaluate its antifungal activity. Materials and methods. The pharmacologically active component is the pharmaceutical substance of the silver salt N-{4-[(1,3-thiazole-2-yl)sulfamoyl]phenyl}-1-phenyl-5-(4-ethoxyphenyl)pyrazole-3-carboxamide. The antifungal activity of the compound was studied by double serial dilutions in a liquid nutrient medium in relation to reference strains of fungi of the genus Candida: Candida albicans NCTC 885-653, Candida krusei RCPGU-1472/310, Candida glabrata RCPGU-1485/47. To determine the antifungal activity of an experimental mild dosage form in relation to a typical strain of fungi of the genus Candida, a three-nesting variant of the agar diffusion method was used. Statistical processing of the results of chemical studies was carried out according to generally accepted methods using standard EXCEL computer programs. Results and discussion. As a result of the conducted research, the composition of an experimental mild dosage form based on the silver salt of pyrazole-3-carboxamide has been substantiated and developed. A technology for the manufacture of ointment has been developed to ensure the quality of the dosage form, its therapeutic activity and stability. Conclusion. Based on technological and microbiological studies, an experimental mild dosage form based on the silver salt of pyrazole-3-carboxamide has been developed with the aim of further introduction into medical practice for the local treatment of dermatomycosis after appropriate studies.

Biochemical and Molecular Identification of Azospirillum brasilense Bacteria and Evaluation of Their Efficiency in Producing Hormones, Dissolving Phosphorus, and Fixing Nitrogen

The study aimed to isolate A.brasilense bacteria from the soil of the rhizosphere of different plants and different locations in Al-Diwaniyah Governorate. They were identified in two ways. The first was the routine method, which included studying the microscopic and cultural characteristics and biochemical tests of the isolates. The second method was molecular, using polymerase chain reaction (PCR) technology and using primers. It also included testing the efficiency of these isolates in dissolving tricalcium phosphate (TCP) on Pikovskaya agar medium, fixing nitrogen in the liquid nutrient medium (N.B), and measuring the amount of hormone production using an HPLC device. The results of isolation and regular and molecular identification the presence of ten isolates of bacteria bearing the characteristics of A. brasilense bacteria, out of fifteen local bacterial isolates, took the following symbols and sequences (Az2, Az3, Az5, Az6, Az7, Az9, Az11, Az12, Az13, Az14), as the results showed confirmation of the identification of the bacterial isolates identified by biochemical tests. Using a specialized primer to amplify the 462bp fragment of the 16S ribosomal RNA gene, the results of testing the efficiency of the bacteria in dissolving phosphate (TCP) showed that the isolate (Az13) outperformed the highest value in its effectiveness in dissolving metallic phosphorus through the diameter of the clear zone around the colony, which was effective in dissolving phosphate of up to 3.89 mm. As for the nitrogen fixation efficiency test, the isolate (Az3) excelled in the amount of fixed nitrogen reaching 12.44 mg.L-1. As for the amount of its production of growth regulators for Auxins, Gibberellins, and Cytokinins, the isolate (Az3) recorded the highest value in the amount of Auxins production ( Indol-3-acetic acid) its concentration reached 34.4 µg.ml-1, and as for the production of the hormone Gibberellins (GA3), the isolate (Az3) recorded the highest value amounting to 34.7 µg.ml-1, as for the production of the hormone Cytokinins (CK), The isolate (Az11) recorded the highest value, amounting to 28.8 µg.ml-1.

Exploring the potential of two Pseudomonas species to produce vincristine from vinblastine via biotransformation

A biotransformation pair consisting of vinblastine: vincristine present in the Catharanthus roseus plant is of immense pharmacological significance. In this study, we successfully transformed vinblastine into vincristine outside the plant using Pseudomonas aeruginosa 8485 and Pseudomonas fluorescens 2421 and evaluated the antiangiogenic potential of thus produced vincristine through the CAM assay. The toxicity assay showed that both Pseudomonas spp. can tolerate varying concentrations (25–100 µl of 1 mg/ml) of vinblastine. The biotransformation was performed in a liquid nutrient broth medium containing vinblastine (25–100 µl), and Pseudomonas spp. inoculums (50–150 µl) by incubating at 30 °C and 37 °C, respectively for 8 days. The process was optimized for substrate and culture concentrations, pH, temperature, and rotation speed (rpm) for the highest conversion. Analysis using LC–MS/MS confirmed the presence of vincristine as a product of the vinblastine biotransformation by two Pseudomonas spp. P. fluorescens 2421 showed a faster conversion rate with 95% of vinblastine transformed within 24 h than P. aeruginosa 8485, which demonstrated a conversion rate of 92% on the 8th day. From LC–MS/MS analysis, the optimal conditions for the reaction were determined as vinblastine (25 µl), microbial inoculums (150 µl or 200 × 106 and 210 × 106 CFU/ml), pH 7.4, rotation speed of 180 rpm, and temperatures of 30 °C and 37 °C with incubation time of 8 days. The vincristine produced exhibited potent antiangiogenic activity in the CAM assay reducing the thickness and branching of blood vessels in a dose-dependent manner. The study concludes that both Pseudomonas spp. showed promise for vincristine production from vinblastine, without compromising its antiangiogenic properties.

Исследование нативной микробиоты рапсового жмыха – потенциального источника промышленных продуцентов

Rapeseed oil production is very active in Russia. Its main by-product is cake: its chemical composition and availability make it an excellent source of nutrients in microbial cultivation to be used as biologically active compounds or as part of functional products. The research objective was to study the native microbiota of rapeseed cake under conditions of high humidity, as well as to describe the morphology of isolated microorganisms and determine their genera by NGS sequencing. The study featured rapeseed cake and microbial colonies isolated after 2, 5, 7, and 9 days of fermentation. The microbial isolates were obtained by the method of surface and deep cultivation on solid and liquid nutrient media, respectively. The metagenomic analysis of the microbial taxonomy involved sequencing on the Illumina platform. The experiment revealed 16 types of colonies with different morphology. Colonies with morphology 1, 3, 8, 12, and 13 were predominant for all fermentation periods, which means that they grew as isolates during the liquid-phase fermentation. The metagenomic analysis revealed at least 28 genera of bacteria in the rapeseed cake suspensions. The highest percentage belonged to Weisella (≤ 45.8% on day 2), Acinetobacter (≤ 40.6% on day 7), Lactobacillus (≤ 15.7% on day 5), Leuconostoc (≤ 15.1% on day 7), Enterococcus (≤ 14.6% on day 5), and Paenibacillus (≤ 16.3% on day 9). The obtained isolates could be of interest as industrial producers of useful metabolites, e.g., enzymes, pigments, organic acids, etc. Further research will identify the microbial species, their useful properties, and optimal cultivation conditions.

Synthesis of phenyl esters 2-oxo-2H-1-benzopyran-3-carboxylic acids as promising antimicrobial agents

Corresponding chloroanhydrides were synthesized by the interaction of coumarin-3-carboxylic and 6-methoxycoumarin-3-carboxylic acids with an excess of thionyl chloride under heating. Due to the quantitative yields and the formation of volatile products within the reaction, chloroanhydrides were used without additional purification in acylation of substituted phenols for the synthesis of phenyl esters of 2-oxo-2H-1-benzopyran-3-carboxylic acids. The reaction was carried out by heating in anhydrous dioxane environment in the presence of pyridine as a catalyst. The structure of the obtained esters was proven using instrumental methods of analysis. The antimicrobial and antifungal activity of the synthesized compounds was studied in vitro by the method of two-fold serial dilutions in liquid and solid nutrient environments. Antimicrobial activity screening showed that the synthesized esters have a moderate activity against gram-negative microorganisms and C. albicans. It was found that the 4-methyl-2-chlorophenyl ester of coumarin-3-carboxylic acid had the greatest bacteriostatic activity against Ps. aeruginosa and Pr. vulgaris, 2-chlorophenyl ester of coumarin-3-carboxylic acid against Ps. aeruginosa and E. coli, coumarin-3-carboxylic acid 4-hydroxyphenyl ester against Pr. vulgaris, and coumarin-3-carboxylic acid 2-isopropyl-5-methylphenyl ester against E. coli at a concentration of 31.25 g/ml. 2-Chlorophenyl ester also showed a bactericidal effect against E. coli. The synthesized compounds also have an antifungal effect against the C. albicans. strain used in the experiment. Thus, 4-methyl-2-chlorophenyl ester, 4-fluorophenyl ester, 4-hydroxyphenyl ester, 2,3-dihydroxyphenyl ester, 2-isopropyl-5-methylphenyl ester of coumarin-3-carboxylic acid are active at a concentration of 31.25 g/ml.

Effect of Different Fertilizer Levels, Biostimulant and Novel Organic Liquid Nutrient on Growth and Yield of Beet Root (Beta vulgaris L.)

Effect of Different Fertilizer Levels, Biostimulant and Novel Organic Liquid Nutrient on Growth and Yield of Beet Root (Beta vulgaris L.)

Физиологические свойства перспективного грибного штамма антагониста возбудителя сухой гнили подсолнечника Т-5 Trichoderma sp.

Dry rot is one of the most dangerous and wide spreading disease on sunflower in last years. Due to the growing demand for environmentally friendly production of agricultural products, the demand for competitive microbiological products is increasing. Since 2020, there are studied and developed environmentally friendly microbiological preparations of a multifunctional type of action against the dry rot pathogen on sunflower Rhizopus oryzae Went & Prins. Geerl. at the V.S. Pustovoit All-Russian Research Institute of Oil Crops. The physiological qualities of a promising antagonist strain of the dry rot pathogen T-5 Trichoderma sp. isolated as a result of stepwise screening were studied during stationary cultivation on liquid nutrient media in order to develop elements of a technological regimen for the production of a microbiological preparation in a preparative form wettable powder. Optimal conditions for surface cultivation of the fungus T-5 Trichoderma sp. on a liquid nutrient medium were determined as following: temperature +25 °C; acidic reaction of the medium (pH 3); glucose and starch as carbon source; source of nitrogen nutrition is corn extract. The media by Rudakova and No. 1 were identified as the best complicated liquid nutrient media.

Культуральные признаки и рост на сложных жидких питательных средах перспективного грибного штамма антагониста М-24 Penicillium sp. возбудителя фомоза подсолнечника

A microbiological method decreasing harmfulness of Phoma rot on sunflower, which is one of the prevailing disease in all regions of crop cultivation, is developed at the V.S. Pustovoit All-Russian Research Institute of Oil Crops. The cultural traits of antagonist fungus of phoma pathogen on sunflower М-24 Penicillium sp. on three agar media and strain growth on four complicated liquid nutrient media were studied at surface cultivation of a strainproducer to develop elements of technological regimen for production of microbiopreparations in a preparative form wettable powder. On the tenth days of cultivation at +25 °С temperature, strong growth of the fungus with abundant conidial sporulation and maximal diameter of a colony was noted on the agar medium by Rudakov. The medium by Rudakov is stated as optimal among complicated liquid nutrient media. In ten days of the surface cultivation, a thick folded mycelial film with an abundant sporulation was formed on this medium as well as maximal weight of a dry mycelium – 1.44 g per 100 ml of nutrient medium vs. 0.20–1.39 g on the other media.

PROBLEMS OF DETERMINING THE MEDICINAL HERBAL REMEDIES ANTIMICROBIAL ACTIVITY AND THEIR SOLUTION METHODS

Intriduction. Currently, the antibiotic resistance development in pathogenic microorganisms remains a global problem. To solve this problem, an active search and development of new antimicrobial drugs, including those of plant origin, is underway. In the many years course of experience in this area, methods used to determine antimicrobial activity are being developed and improved, however, not all of them are suitable for determining the activity of biologically active substances of plant origin. The purpose of the study. To summarize information about existing methods for determining antimicrobial activity under in vitro experimental conditions. Material and methods. The article is based on publication materials from the PubMed and E-library databases, search.rsl. The literary search was carried out by keywords: antimicrobial activity, antibacterial effect, antibiotic, herbal preparations. The review includes articles that are relevant to the research topic and have been published over the past 10 years. Results and discussion. The article describes the main methods for determining antimicrobial activity in vitro and determines the possibility of using these methods in relation to herbal remedies. Conclusions. The findings indicated that the choice of the research method should depend primarily on the object under study and the type of microorganism in respect of which the activity is determined. Most of the developed and widely used methods for determining antimicrobial activity do not allow an adequate assessment of the activity of herbal remedies. Thus, when working with herbal remedies, the methods of double serial dilutions in liquid nutrient media with the use of indicators and the developing direction of activity research on biofilms can be considered the most accurate.

Integrated Nutrient Management in Muskmelon: A Comprehensive Field Study

The present study aims to describe the effects of integrated nutrient management (INM) on Madhumita variety of muskmelon cultivation in terms of plant growth, fruit yield, and quality. The experiment has been carried out in the crop field located in the North Konkan region of Maharashtra, India. This case study involved seven different treatments (T1 to T7), each with varying nutrient application regimes. Certain observational data, such as vine length, number of leaves per plant, leaf length, days to 50% flowering, number of fruits per plant, fruit length, fruit width, fruit weight, and fruit yield, were recorded for three replications over the course of the experiment. The results of statistical analysis revealed significant differences, with specific treatments demonstrating T6, which included Vermicompost at 5 tons/ha, 75% of the recommended dose of fertilizers (RDF), and 1% NOVEL prime organic liquid nutrient, consistently outperformed the other treatments groups. The findings highlight the utility of integrated nutrient management. It helps in understanding and optimizing the application of nutrients to boost crop productivity and promote sustainability.

STUDY OF THE EFFECT OF BACTERIA OF THE GENUS BACILLUS ON THE CULTURE OF RICE AND CORN SEEDS IN VITRO

The aim of the study was to investigate the effect of bacteria strains Bacillus megaterium ONU500, Bacillus velezensis ONU553, Bacillus pumilus ONU554, Bacillus subtilis ONU559 on the germination and growth of rice and corn seeds under sterile conditions. Materials and methods. Three-day cultures of the four strains were grown on LB liquid nutrient medium in a thermostat at 28 °C and the seeds of model plants were sterilized according to the standard scheme. The seeds were placed in 1% solutions of bacterial suspensions (106 CFU/ml) of each strain and inoculated for 1 hour. Results. The experiment results on both model plants indicate significant potential of the bacteria B. megaterium ONU500, B. velezensis ONU553, B. pumilus ONU554 as growth and development stimulators for plants. B. subtilis ONU559 is recommended for further study and clarification of its impact on plants in subsequent research. Conclusion. The most positive, stimulating effect on the indicators of germination, growth, and development of rice and corn seeds is exerted by inoculation with the strain B. megaterium ONU500 (for rice: increase in shoot length by 36.5%, root by 29%; for corn: 50% and 69% respectively). Further study of the influence of B. velezensis ONU553 is promising for rice cultivation, and for corn – B. pumilus ONU554.

In vitro and in vivo screening of bacterial species from contaminated soil for heavy metal biotransformation activity

Heavy metals (HMs) are widely used in various industries. High concentrations of HMs can be severely toxic to plants, animals and humans. Microorganism-based bioremediation has shown significant potential in degrading and detoxifying specific HM contaminants. In this study, we cultivated a range of bacterial strains in liquid and solid nutrient medium containing different concentrations of different HMs to select and analyze bacteria capable of transforming HMs. The bacterial strains most resistant to selected HMs and exhibiting the ability to remove HMs from contaminated soils were identified. Then, the bacterial species capable of utilizing HMs in soil model experiments were selected, and their ability to transform HMs was evaluated. This study has also generated preliminary findings on the use of plants for further removal of HMs from soil after microbial bioremediation. Alcaligenes faecalis, Delftia tsuruhatensis and Stenotrophomonas sp. were selected for their ability to grow in and utilize HM ions at the maximum permissible concentration (MPC) and two times the MPC. Lysinibacillus fusiformis (local microflora) can be used as a universal biotransformation tool for many HM ions. Brevibacillus parabrevis has potential for the removal of lead ions, and Brevibacillus reuszeri and Bacillus safensis have potential for the removal of arsenic ions from the environment. The bacterial species have been selected for bioremediation to remove heavy metal ions from the environment.

Study on isolating, breeding, and cultivation of Xylaria nigripes (Klotzsch) Cooke

The Xylaria nigripes fungus is one of the medicinal materials that was used in traditional medicine. Extracts from the mycelium and fruiting bodies of the X. nigripes showed protecting cells, preventing DNA damage, and reducing the programmed death cell rate. In this study, the fruiting bodies of the X. nigripes were collected to isolate, propagate in the liquid medium, and then cultured to induce the fruiting body formation in the rice medium. The results showed that the X. nigripes was successfully isolated on PDAY (Potato Dextrose Agar Yeast Extract) medium, and the mycelium and spore of the X. nigripes had unique characteristics of the species. The biomass of X. nigripes grew well in a liquid nutrient medium containing 20g glucose, 1g MgSO4.7H2O, 2g KH2PO4, and 5g peptone, reaching the best mass after 21 to 28 days. Using an initial cultured liquid of X. nigripes to culture on rice medium, fruiting bodies were formed and developed after 14 days of culture. This result could potentially be applied to the production of X. nigripes biomass via mycelium and fruit bodies for application in medicine.

A two-phase thin-film model for cell-induced gel contraction incorporating osmotic effects

We present a mathematical model of an experiment in which cells are cultured within a gel, which in turn floats freely within a liquid nutrient medium. Traction forces exerted by the cells on the gel cause it to contract over time, giving a measure of the strength of these forces. Building upon our previous work (Reoch et al. in J Math Biol 84(5):31, 2022), we exploit the fact that the gels used frequently have a thin geometry to obtain a reduced model for the behaviour of a thin, two-dimensional cell-seeded gel. We find that steady-state solutions of the reduced model require the cell density and volume fraction of polymer in the gel to be spatially uniform, while the gel height may vary spatially. If we further assume that all three of these variables are initially spatially uniform, this continues for all time and the thin film model can be further reduced to solving a single, non-linear ODE for gel height as a function of time. The thin film model is further investigated for both spatially-uniform and varying initial conditions, using a combination of analytical techniques and numerical simulations. We show that a number of qualitatively different behaviours are possible, depending on the composition of the gel (i.e., the chemical potentials) and the strength of the cell traction forces. However, unlike in the earlier one-dimensional model, we do not observe cases where the gel oscillates between swelling and contraction. For the case of initially uniform cell and gel density, our model predicts that the relative change in the gels’ height and length are equal, which justifies an assumption previously used in the work of Stevenson et al. (Biophys J 99(1):19–28, 2010). Conversely, however, even for non-uniform initial conditions, we do not observe cases where the length of the gel changes whilst its height remains constant, which have been reported in another model of osmotic swelling by Trinschek et al. (AIMS Mater Sci 3(3):1138–1159, 2016; Phys Rev Lett 119:078003, 2017).

Assessment of the Adsorption Activity of Bacterial Cells Using Yersinia pseudotuberculosis Model

Currently, the Russian Anti-Plague Institute “Microbe” produces diagnostic immunoglobulins used in laboratory diagnostics of plague pathogen. One of the important stages in obtaining this category of drugs is the process of adsorption and removal of cross-reacting antibodies to increase the specificity of the drug. For this purpose, inactivated cells of Yersinia pseudotuberculosis strains are used.The aim of the work was to assess the possibility of using immunochemical methods to analyze the adsorption properties of bacterial cells, followed by an assessment of the impact of cultivation method and conditions, and the variant of the strain used on the adsorption properties of bacterial cells.Materials and methods. Cultivation was carried out on solid and liquid nutrient media; cells were inactivated by temperature and chemical exposure. Adsorption activity was assessed using immunoblotting and inhibitory enzyme-linked immunosorbent assay. Statistical processing of the results was performed using two-factor analysis of variance.Results and discussion. The suitability of immunoblotting and inhibitory ELISA methods for qualitative and quantitative assessment of the adsorption properties of bacterial cells has been demonstrated. It has been established that the adsorption properties of bacterial cells are influenced by the method of inactivation and the application of substrate feeding; the method of cultivation does not affect the adsorption properties of cells.