Nutrient Medium Research Articles

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).

Silver nanoparticle-induced in vitro flowering in Dendrocalamus strictus (Roxb.) nees and genetic fidelity assessment of regenerants using molecular markers.

Dendrocalamus strictus (Roxb.) Nees, generally referred to as 'Male bamboo,' is a globally prevalent and highly significant species of bamboo. It is a versatile species and possesses notable industrial significance. However, despite its numerous applications, the production of this plant is insufficient to fulfill the worldwide demand. The challenges that impede the dissemination of D. strictus encompass the unpredictable blooming pattern (30-70 years), low seed production, and limited seed viability. Therefore, tissue culture presents a reliable and effective option for the mass production of standardized planting material. This study investigated the effects of silver nanoparticles (AgNPs) at a concentration of 6.0 mg L- 1 in the Murashige and Skoog (MS) nutrient medium fortified with pre-optimized plant growth regulators (3.0 mg L- 1 6-benzylaminopurine + 0.5 mg L- 1 α-naphthalene acetic acid) on the induction of flowering in a controlled environment in D. strictus. The use of AgNPs in the media induced a maximum of 14 inflorescences per culture vessel, 9 flowers per inflorescence, and improved the performance of the micropropagated plantlets during acclimatization in the greenhouse and field. The ISSR and SCoT amplified polymorphic DNA analysis of the regenerants resulted in the formation of 49 bands (300 to 2000bp size) and 36 scorable bands (350 to 2000bp) respectively. All the PCR amplicons produced by SCoT and ISSR were monomorphic confirming the genetic uniformity of the tissue cultured plants of D. strictus with the mother plant. It can be inferred that the incorporation of AgNPs during the shoot proliferation phase has the potential to stimulate in vitro flowering in D. strictus. This finding could provide valuable insights into innovative strategies for enhancing crop productivity and genetic manipulation for accelerated breeding and agricultural advancement.

Nutrients recovery from dairy wastewater by Chlorella vulgaris and comparison of the lipid's composition with various chlorella strains for biodiesel production.

Microalgae biomass is regarded as a promising feedstock for biodiesel production. The biomass lipid content and fatty acids composition are among the main selective criteria when screening microalgae strains for biodiesel production. In this study, three strains of Chlorella microalgae (C. kessleri, C. sorokiniana, C. vulgaris) were cultivated nutrient media with different nitrogen contents, and on a medium with the addition of dairy wastewater. Moreover, microalgae grown on dairy wastewater allowed the removal of azote and phosphorous. The removal efficiency of 90%, 53% and 95% of ammonium nitrogen, total nitrogen and phosphate ions, respectively, were reached. The efficiency of wastewater treatment from inorganic carbon was 55%, while the maximum growth of biomass was achieved. All four samples of microalgae had a similar fatty acid profile. Palmitic acid (C16:0) was the most abundant saturated fatty acid (SFA), and is suitable for the production of biodiesel. The main unsaturated fatty acids (UFA) present in the samples were oleic acid (C18:1 n9); linoleic acid (C18:2 n6) and alpha-linolenic acid (C18:3 n3), which belong to omega-9, omega-6, omega-3, respectively.

Ordered Changes in Methane Production Performance and Metabolic Pathway Transition of Methanogenic Archaea under Gradually Increasing Sodium Propionate Stress Intensity

This study examined the impact of sodium propionate concentration (0–40 g/L) on the methanogenic archaea in an inoculum which was cultured in basal nutrient medium, exploring its mechanisms and nonlinear stress intensity. The results indicated that at low concentrations, propionate-maintained homeostasis of the anaerobic digestion (AD) system and enriched Methanosaeta. However, when the concentration exceeded 16 g/L, the stability of the AD system was disrupted. The methanogenic pathway shifted towards a predominantly hydrogenotrophic pathway, resulting in a significant increase in methane yield. Below concentrations of 28 g/L, the AD system gradually enhanced its ability to utilize propionate in an orderly manner. At concentrations of 24–28 g/L, genera (e.g., Advenella and Methanosarcina) were enriched to adapt to the high-VFA environment. This was accompanied by a significant upregulation of genes related to the methylotrophic and hydrogenotrophic pathways, effectively mitigating propionate inhibition and enhancing methanogenesis. Conversely, excess concentrations (>30 g/L) suppressed methanogenesis-related genes and led to methane production arrest despite activating specialized propionate-metabolizing bacteria such as genus Pelotomaculum schinkii. As such, an increase in the stress intensity of propionate promotes a change in the metabolic pathways of methanogens and increases methane production; however, excessive sodium propionate was not conducive to maintaining the steady state of the system.

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.

Effect of dehydration method on the micro- and nanomorphological properties of bacterial cellulose produced by Medusomyces gisevii on different substrates

AbstractMany important properties of bacterial cellulose (BC), such as moisture absorption capacity, elasticity and tensile strength, largely depend on its structure. This paper presents a study on the effect of the drying method on BC films produced by Medusomyces gisevii using two different procedures: room temperature drying (RT, (24 ± 2 °C, humidity 65 ± 1%, dried until a constant weight was reached) and freeze-drying (FD, treated at − 75 °C for 48 h). BC was synthesized using one of two different carbon sources—either glucose or sucrose. Structural differences in the obtained BC films were evaluated using atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray diffraction. Macroscopically, the RT samples appeared semi-transparent and smooth, whereas the FD group exhibited an opaque white color and sponge-like structure. SEM examination showed denser packing of fibrils in FD samples while RT-samples displayed smaller average fiber diameter, lower surface roughness and less porosity. AFM confirmed the SEM observations and showed that the FD material exhibited a more branched structure and a higher surface roughness. The samples cultivated in a glucose-containing nutrient medium, generally displayed a straight and ordered shape of fibrils compared to the sucrose-derived BC, characterized by a rougher and wavier structure. The BC films dried under different conditions showed distinctly different crystallinity degrees, whereas the carbon source in the culture medium was found to have a relatively small effect on the BC crystallinity. Graphical Abstract

In English

Changes in the light absorption spectrum when mixing colloids of Ag nanoparticles with a diameter of 7 nm in a quercetin shell with a nutrient medium were studied in the present article. Colloids of silver nanoparticles were prepared by chemical reduction of AgNO3 silver salt with sodium tetrahydroborate (NaBH4) in an aqueous solution. Quercetin is a flavonoid of plant origin. It was chosen to stabilize nanoparticles due to its capability to form complexes with metals. The quercetin shell is capable to preserve the bactericidal effect of silver NPs on bacteria and weaken their toxic effect on healthy cells of the human body. The absorption spectra of solutions from which nanoparticle colloids were synthesized were used to control the synthesis result. The Luria-Bertani nutrient medium was studied in the work. Absorption spectra of the nutrient medium and nanoparticle colloids were again obtained immediately before mixing. Then, the nutrient medium and the nanoparticle colloid were mixed in volume proportion 1:1, and the absorption spectrum of the mixture was mesured. The absorption spectrum of the mixture did not reproduce a simple overlay of the nanoparticle colloid spectrum on the absorption spectrum of the nutrient medium. To describe the experimental spectra, a colloid of stabilized silver nanoparticles, a nutrient medium, and a mixture of a colloid and a nutrient medium were considered by nanocomposites of various organic and inorganic nanoparticles in a liquid. As a result, experimental absorption spectra were theoretically approximated by related to these nanoparticles elementary oscillators. The error of the discrepancy between experimental and simulated spectra did not exceed 3%. Analysis of the complex spectra of the mixture of the nanoparticle colloid and the nutrient medium has shown that the frequency of the localized plasmon resonance in the nanoparticles most likely does not change. It means that for studying the effect of nanoparticles on biological objects (microbes or viruses), the wavelength of external irradiation must be chosen equal to the wavelength of LPR in the colloid.

Impact of Temperature and Nutrient Medium on Confused Flour Beetle Development

Impact of Temperature and Nutrient Medium on Confused Flour Beetle Development

Improvement of the potato seed production system on a virus-free basis in Almaty region

This article presents data on the induction of potato microtubers and the potency of different varieties to form microtubers in vitro. It has been established that the main factors influencing the process of tuberization in potato regenerated plants are: the concentration of carbohydrates and plant growth regulators in the nutrient medium and physiological state. Experiments were carried out to obtain microtubers from regenerated plants of 4 potato varieties of domestic selection (Alliance, Babaev, Miras and Pamyaty Konaeva) for the selection of virus-free primary material for seed production.As a result, a modified nutrient medium Murasige and Skoog (MS) containing 20 mg/L orotic acid was developed to accelerate the formation of microtuber formation of potato plants in vitro.

Влияние геотермальной воды в составе твердых сред культивирования на морфологические свойства дрожжей рода Saccharomyces

The influence of geothermal waters located on the territory of the city of Makhachkala (Republic of Dagestan), in the composition of solid cultivation media, on the cultural and morphological features of genus Saccharomyces yeast was studied. Changes in cell properties and the formation of specific parameters of giant yeast colonies S. cerevisiae Y-503, S. cerevisiae DAW-3a, S. oviformis M-12x have been established. For YPD and PD media, as a result of a series of experiments, optimal options were selected containing geothermal and distilled water in a ratio of 1:1 (well No. 36) and 2:1 (well No. 26). It was shown that the YPD medium was optimal for yeast growth, while in the population of the tetraploid Y-503 strain, the average cell size was slightly larger than cell strain M-12x and significantly exceeded the DAW-3a values. Installed that the use of diluted water from well No. 36 in the cultivation medium is most effective and leads to accelerated growth of yeast colonies. In the variant geothermal / distilled water, this indicator exceeded the control by 1.3 (Y-503, M-12x) times; in the variant with geothermal water without dilution - by 1.6 (Y-503) and 1.4 (M-12x) times. The cells of the S. cerevisiae Y-503 strain, regardless of the medium used, are characterized by the presence of various forms, including elongated ones; DAW-3a - exceptionally rounded; S. oviformis M-12x - rounded and oval shapes. A comparative analysis of the parameters of the colonies showed that all variants are characterized by a rounded shape, a radially striated surface; flat, with a convex center profile; light beige color and pasty, spreadable texture. As a result of our research, a modified nutrient medium PD has been developed - an agar for growing yeast, containing geothermal water from well No. 36 of the Makhachkala field as an additional source of mineral and organic compounds. The proposed composition of the medium is of interest for its further use in microbiological studies.

Разработка технологии получения нового биоэлектрокатализатора – «грубого» экстракта Saccharomyces cerevisiae

“Crude” extracts obtained by ultrasonic disintegration of microorganisms are promising bioelectrocatalysts. Extracts from Saccharomyces cerevisiae are of particular interest because they may contain a significant number of enzyme systems that oxidize simple carbohydrates such as glucose. A technology for producing “crude” protein extracts of Saccharomyces cerevisiae has been developed. The percentage of glucose added to the nu-trient medium, as well as the composition of the buffer solution at the resuspending stage, the power and time of ultrasonic disintegration of biomass, the rate and time of centrifugation during separation of the sediment of destroyed cells from the filler fluid have a significant effect on the enzymatic activity of the resulting “crude” extract.

Клональное микроразмножение лесных ягодных растений рода Rubus

Cloudberry (Rubus chamaemorus L.) and arctic raspberry (Rubus arcticus L.) are highly nutritional and medicinal but lowyield berries, with some populations being on the verge of extinction. Micropropagation biotechnologies are cost-effective and may provide healthy and plentiful planting material for these valuable berries. Clonal micropropagation of cloudberry and arctic raspberry requires new methods adapted for Russian varieties. This research featured the effect of sterilizing agents on the survival rate of explants of R. chamaemorus and R. arcticus, as well as the effect of growth regulators in the nutrient medium on their organogenesis in vitro.
 Berries obtained from regenerant plants of R. chamaemorus (Arkhangelsk and Vologda varieties) and R. arcticus (Sofia and Galina varieties) underwent a biochemical analysis. Further research involved the effect of sterilizing agents and exposure time on the viability of explants, as well as the effect of the nutrient medium composition and the concentration of growth regulators on the development of microshoots and roots in vitro.
 In case of lateral buds, the highest survival rate of both types of explants (80–96%) belonged to the samples sterilized with 0.2% silver nitrate and 5% Lysoformin 3000 for 15 min. In case of etiolated shoots (79–100%), it was the samples treated with 0.2% silver nitrate, 0.01% Nika 2, and 5% Lysoformin 3000 for 10 min. The maximal total length of microshoots in R. chamaemorus (19.4–22.7 cm) was registered at 0.1 mg/L Cytodef in the Murashige and Skoog medium. The maximal total length of roots (46.0–56.6 cm) was obtained when the medium contained 0.5 mL/L indolylacetic acid. As for R. arcticus, the maximal total lengths of microshoots (22.4–22.8 cm) and roots (86.6–89.3 cm) occurred at the same concentrations of growth regulators on 1/2 Murashige and Skoog medium.
 In this research, Cytodef and indolylacetic acid applied in the process of clonal micropropagation of R. chamaemorus and R. arcticus made it possible to increase the yield of high-quality planting material for commercial plantations.

Feasibility of Parallel Cropping of Black Gram with Pigeon pea in Central Trait of Uttar Pradesh

An experiment was laid out during two consecutive Kharif seasons of 2016-2017 and 2017-18 at Soil Conservation and Water Management Farm, C.S. Azad University of Agriculture and Technology, Kanpur. The main objective was to find out the yields of main crop of pigeonpea and black gram and their economic in term of net return. The soil analysis indicated the medium nutrients status. The cropping system i.e., pigeonpea sole, black gram sole and pigeonpea + black gram (1+1) additive series were tested. The total productivity of pigeonpea + black gram was maximum (23.53 q/ha) in comparison to pure crop of pigeonpea (17.34 q/ha) and black gram pure (9.44 q/ha). The study of pooled data of economic display that maximum cost of cultivation Rs. 57876/- ha observed under intercropping of pigeonpea + black gram system. The highest gross return Rs. 134024/ha, net return Rs. 76148/ha and BCR 2.32 were also noted under pigeonpea + black gram (1+1) additive series.

Effects of Variable Electrical Conductivity Levels in Hydroponic Nutrient Solutions on Morphological and Physiochemical Characteristics of Cucumber Plants in Advanced Greenhouse Cultivation

Cucumber (Cucumus sativus L.) is a fruit of the Cucurbitaceae family that is refreshing, low in calories, and offers various health benefits due to its rich nutritional profile. However, high-tech hydroponic greenhouse production of cucumber is nutrient-intensive and requires efficient management of electrical conductivity (EC) in the growing medium. In this study, three different EC levels (1.3, 2.6, and 3.6 dS/m) were applied to the nutrient medium of hydroponically grown Lebanese and Continental varieties of cucumber. The experiment did not have a significant impact on the number of fruits (p=0.744, p=0.163) or leaves per plant (p=0.252, p=0.377) at varying EC levels. However, in the Continental variety, pH (0.001***) and osmolality (0.005**) were significantly different among the three varied EC levels. High EC levels in the nutrient medium resulted in reduced TSS, pH, and osmolality of the fruit juice. Although the plants grown in low EC conditions produced almost the same number of fruits and leaves per plant as those grown in optimal EC conditions (2.6 dS/m), the physio-chemical attributes of the cucumbers were of inferior quality.

Abstract 388: Identifying synthetic lethalities in GCN2 KO tumors using an in vivo targeted CRISPRi screen

Abstract The integrated stress response (ISR) is an intracellular signaling pathway that fosters cell adaptation to diverse stresses. The ISR is mediated by a family of four eIF2 kinases that each sense distinct cellular stresses. Activation of the eIF2 kinases results in reprogrammed gene expression through translational and transcriptional mechanisms that help prevent stress damage. Previously, we reported that prostate cancer (PCa) cells rely on GCN2 eIF2 kinase for maintenance of amino acid (AA) homeostasis to sustain growth (Cordova et al., 2022 eLife 11:e81083). GCN2 inhibition through pharmacological or genetic means results in decreased expression of AA transporters, depletion of intracellular AAs, and reduced growth of PCa cells in culture and mouse xenograft models. Although loss of GCN2 results in a significant reduction in PCa cell growth, minimal cell death is observed. We hypothesize that loss of GCN2 in PCa cells results in vulnerabilities that can be exploited and targeted to induce cell death. To optimize GCN2-targeted therapies for PCa, we utilized a targeted CRISPR-interference (CRISPRi) screen in castration-resistant 22Rv1 cells with functional wild type (WT) GCN2 or those with it deleted (GCN2 KO). The CRISPRi screen was performed in cells grown in culture or grown as tumor xenografts in mice and featured a guide library targeting genes that encode druggable targets, including kinases, phosphatases, and metabolic enzymes. While reduced expression of 152 genes was synthetically lethal with loss of GCN2 in the in vitro screen, more genes (202) were synthetically lethal with loss of GCN2 in vivo. Of note, reduced expression of many metabolic enzymes was synthetically lethal with GCN2 ablation only in the in vivo screen, potentially due to the abundance of nutrients in standard culture media. A group of six metabolism-related genes, identified as hits in the in vivo screen and targets of FDA-approved drugs, were selected for follow-up studies. One of these metabolic enzymes was GART, a trifunctional enzyme that carries out 3 of the 10 enzymatic steps in de novo purine biosynthesis. Based on our findings showing that GCN2 maintains AA levels to support nucleotide pools in PCa cells, we initially focused on this critical enzyme. Inhibition of GART using antifolates, including the FDA-approved Pemetrexed, resulted in minimal cell death of parental and GCN2 KO PCa cells cultured in standard culture media. However, when cultured in reduced nutrient media that better mimicked reduced nutrient availability in vivo, GART inhibition resulted in selective death of GCN2 KO cells. Our CRISPRi screening strategy uncovers new vulnerabilities in GCN2-inhibited PCa cells and reveals a general strategy to identify actionable targets with the potential to combine with GCN2 inhibitors for the treatment of PCa. Citation Format: Noah R. Sommers, Ricardo A. Cordova, Angela J. Klunk, Ronald C. Wek, Kirk A. Staschke. Identifying synthetic lethalities in GCN2 KO tumors using an in vivo targeted CRISPRi screen [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 388.

Dissecting the Roles of the Cytokinin Signaling Network: The Case of De Novo Shoot Apical Meristem Formation.

Numerous biotechnological applications require a fast and efficient clonal propagation of whole plants under controlled laboratory conditions. For most plant species, the de novo regeneration of shoots from the cuttings of various plant organs can be obtained on nutrient media supplemented with plant hormones, auxin and cytokinin. While auxin is needed during the early stages of the process that include the establishment of pluripotent primordia and the subsequent acquisition of organogenic competence, cytokinin-supplemented media are required to induce these primordia to differentiate into developing shoots. The perception of cytokinin through the receptor ARABIDOPSIS HISTIDINE KINASE4 (AHK4) is crucial for the activation of the two main regulators of the establishment and maintenance of shoot apical meristems (SAMs): SHOOTMERISTEMLESS (STM) and the WUSCHEL-CLAVATA3 (WUS-CLV3) regulatory circuit. In this review, we summarize the current knowledge of the roles of the cytokinin signaling cascade in the perception and transduction of signals that are crucial for the de novo establishment of SAMs and lead to the desired biotechnological output-adventitious shoot multiplication. We highlight the functional differences between individual members of the multigene families involved in cytokinin signal transduction, and demonstrate how complex genetic regulation can be achieved through functional specialization of individual gene family members.

Development of an Integrated Bioprocess System for Bioethanol and Arabitol Production from Sugar Beet Cossettes.

An innovative integrated bioprocess system for bioethanol production from raw sugar beet cossettes (SBC) and arabitol from remaining exhausted sugar beet cossettes (ESBC) was studied. This integrated three-stage bioprocess system is an example of the biorefinery concept to maximise the use of raw SBC for the production of high value-added products such as sugar alcohols and bioethanol. The first stage of the integrated bioprocess system was simultaneous sugar extraction from SBC and its alcoholic fermentation to produce bioethanol in an integrated bioreactor system (vertical column bioreactor and stirred tank bioreactor) containing a high-density suspension of yeast Saccharomyces cerevisiae (30 g/L). The second stage was the pretreatment of ESBC with dilute sulfuric acid to release fermentable sugars. The resulting liquid hydrolysate of ESBC was used in the third stage as a nutrient medium for arabitol production by non-Saccharomyces yeasts (Spathaspora passalidarum CBS 10155 and Spathaspora arborariae CBS 11463). The obtained results show that the efficiency of bioethanol production increased with increasing temperature and prolonged residence time in the integrated bioreactor system. The maximum bioethanol production efficiency (87.22 %) was observed at a time of 60 min and a temperature of 36 °C. Further increase in residence time (above 60 min) did not result in the significant increase of bioethanol production efficiency. Weak acid hydrolysis was used for ESBC pretreatment and the highest sugar yield was reached at 200 °C and residence time of 1 min. The inhibitors of the weak acid pretreatment were produced below bioprocess inhibition threshold. The use of the obtained liqiud phase of ESBC hydrolysate for the production of arabitol in the stirred tank bioreactor under constant aeration clearly showed that S. passalidarum CBS 10155 with 8.48 g/L of arabitol (YP/S=0.603 g/g and bioprocess productivity of 0.176 g/(L.h)) is a better arabitol producer than Spathaspora arborariae CBS 10155. An innovative integrated bioprocess system for the production of bioethanol and arabitol was developed based on the biorefinery concept. This three-stage bioprocess system shows great potential for maximum use of SBC as a feedstock for bioethanol and arabitol production and it could be an example of a sustainable 'zero waste' production system.

Mitigation of arsenic accumulation in crop plants using biofertilizer.

Elevated levels of arsenic in crop plants have been found in various regions worldwide, especially where agricultural soils have been affected by arsenic-enriched aquifers and human activities including mining, smelting, and pesticide application. Given the highly toxic nature of arsenic, remediation should be carried out immediately to reduce this potentially toxic element transport from soil to crop plants. This study focused on the utilization of biofertilizer which is a combination of arsenic-accumulating microorganisms and adsorbent (carrier) in order to achieve high efficiency of arsenic immobilization and ability to apply in the field. Thirty-two bacterial strains were isolated from 9 soil samples collected from the Dongjin and Duckum mining areas in Korea using a nutrient medium amended with 2 mM sodium arsenite. Among isolates, strain DE12 identified as Bacillus megaterium exhibited the greatest arsenic accumulation capacity (0.236 mg/g dry biomass) and ability to resist up to 18 mM arsenite. Among the three agricultural waste adsorbents studied, rice straw was proved to have a higher adsorption capacity (0.104 mg/g) than rice husk and corn husk. Therefore, rice straw was chosen to be the carrier to form biofertilizer together with strain DE12. Inoculation of biofertilizer in soil showed a reduction of arsenic content in the edible part of lettuce, water spinach, and sweet basil by 17.5%, 34.1%, and 34,1%, respectively compared to the control group. The use of biofertilizer may open up the potential application in the field for other food plants.

Evaluation of nanoparticle albumin-bound paclitaxel loaded macrophages for glioblastoma treatment based on a microfluidic chip.

Introduction: Glioblastoma (GBM) is a primary brain malignancy with a dismal prognosis and remains incurable at present. In this study, macrophages (MΦ) were developed to carry nanoparticle albumin-bound paclitaxel (nab-PTX) to form nab-PTX/MΦ. The aim of this study is to use a GBM-on-a-chip to evaluate the anti-GBM effects of nab-PTX/MΦ. Methods: In this study, we constructed nab-PTX/MΦ by incubating live MΦ with nab-PTX. We developed a microfluidic chip to co-culture GBM cells and human umbilical vein endothelial cells, mimicking the simplified blood-brain barrier and GBM. Using a syringe pump, we perform sustainable perfusion of nutrient media. To evaluate the anti-GBM effects nab-PTX/MΦ, we treated the GBM-on-a-chip model with nab-PTX/MΦ and investigated GBM cell proliferation, migration, and spheroid formation. Results: At the chosen concentration, nab-PTX did not significantly affect the viability, chemotaxis and migration of MΦ. The uptake of nab-PTX by MΦ occurred within 1h of incubation and almost reached saturation at 6h. Additionally, nab-PTX/MΦ exhibited the M1 phenotype, which inhibits tumor progression. Following phagocytosis, MΦ were able to release nab-PTX, and the release of nab-PTX by MΦ had nearly reached its limit at 48h. Compared with control group and blank MΦ group, individual nab-PTX group and nab-PTX/MΦ group could inhibit tumor proliferation, invasion and spheroid formation. Meanwhile, the anti-GBM effect of nab-PTX/MΦ was more significant than nab-PTX. Discussion: Our findings demonstrate that nab-PTX/MΦ has a significant anti-GBM effect compared to individual nab-PTX or MΦ administration, suggesting MΦ as potential drug delivery vectors for GBM therapy. Furthermore, the developed GBM-on-a-chip model provides a potential ex vivo platform for innovative cell-based therapies and tailored therapeutic strategies for GBM.

Initial Biomass Effect of Azolla caroliniana Culture on Performance in the Southern Kyrgyzstan Conditions

The object of the study was Azolla caroliniana Willd., collected from reservoirs of collector-drainage networks in the vicinity of Osh (Ak-Buura river basin), and also grown in laboratory conditions. To determine the initial biomass of the culture, Azolla caroliniana was grown outdoors in tray units with an area of 1 m2 of water surface, a capacity of 500 l, a depth of 50 cm and a nutrient medium prepared from chicken manure (5 g/l), which was renewed every 5 days. The initial biomass of the Azolla culture added to the trays in option I was 100 g/m2, in option II 200 g/m2, option III 300 g/m2, option IV 400 g/m2, option V 500 g/m2, option VI 600 g/m2, VII option 700 g/m2. The A. caroliniana high performance in variants III and IV is the result of its daily growth rate. As a result, the daily increase was 129.0±0.4 g/m2in option III, and 112.4±0.3 in option IV. With a low biomass (in options I and II), azolla does not have time to fully use the available nutrient medium; due to the excess nutrient medium, other aquatic plants and algae develop strongly. In this regard, the growth and development of Azolla shoots and rhizoids slows down. In the III and IV variants of the Azolla experiment, due to the complete absorption of nutrients, normal development of the root structure and shoots occurs; accordingly, the daily growth rate of raw biomass was higher than in the other variants. Thus, when growing Azolla caroliniana in field conditions or in greenhouses, it is advisable to use 300-400 g of initial biomass per 1 m2 of water surface.