Magnesium sulfate paste

This study demonstrates that Lactobacillus can produce exopolysaccharides (EPSs) using alternative carbon sources, such as sugarcane molasses and glycerol. After screening 22 strains of Lactobacillus to determine which achieved the highest production of EPS based on dry weight at 37 °C, the strain Ke8 (L. casei) was selected for new experiments. The EPS obtained using glycerol and glucose as carbon sources was classified as a heteropolysaccharide composed of glucose and mannose, containing 1730 g.mol-1, consisting of 39.4% carbohydrates and 18% proteins. The EPS obtained using molasses as the carbon source was characterized as a heteropolysaccharide composed of glucose, galactose, and arabinose, containing 1182 g.mol-1, consisting of 52.9% carbohydrates and 11.69% proteins. This molecule was characterized using Size Exclusion Chromatography (HPLC), Gas chromatography-mass spectrometry (GC-MS), Fourier-transform infrared spectroscopy (FTIR), and proton nuclear magnetic resonance spectroscopy (1H-NMR). The existence of polysaccharides was confirmed via FT-IR and NMR analyses. The results obtained suggest that Lacticaseibacillus casei can grow in media that use alternative carbon sources such as glycerol and molasses. These agro-industry residues are inexpensive, and their use contributes to sustainability. The lack of studies regarding the use of Lacticaseibacillus casei for the production of EPS using renewable carbon sources from agroindustry should be noted.

Abstract licence: CC BY

Several studies have demonstrated, both in vitro and in animal models, the anti-tumor efficacy of high-dose ascorbate treatment against a variety of tumor entities, including glioblastoma, the most common and aggressive primary malignant brain tumor. The aim of this study was to investigate the effects of high-dose ascorbate as well as dehydroascorbic acid on human glioblastoma cell lines and to evaluate different treatment conditions for the combined administration of ascorbate with magnesium (Mg2+) and iron (Fe3+). Intracellular levels of reactive oxygen species and the induction of cell death following ascorbate treatment were also investigated. We demonstrated high cytotoxicity and antiproliferative efficacy of high-dose ascorbate in human glioblastoma cells, whereas much weaker effects were observed for dehydroascorbic acid. Ascorbate-induced cell death was independent of apoptosis. Both the reduction in cell viability and the ascorbate-induced generation of intracellular reactive oxygen species could be significantly increased by incubating the cells with Fe3+ before ascorbate treatment. This work demonstrates, for the first time, an increase in ascorbate-induced intracellular ROS formation and cytotoxicity in human glioblastoma cells by pre-treatment of the tumor cells with ferric iron, as well as caspase-3 independence of cell death induced by high-dose ascorbate. Instead, the cell death mechanism caused by high-dose ascorbate in glioblastoma cells shows evidence of ferroptosis. The results of the present work provide insights into the efficacy and mode of action of pharmacological ascorbate for the therapy of glioblastoma, as well as indications for possible approaches to increase the effectiveness of ascorbate treatment.

Abstract licence: CC BY

Siderophores, specialized iron-chelating molecules produced by Bacillus amyloliquefaciens D5, were investigated for their role in enhancing plant defense mechanisms against Cercospora canescens in mung bean (Vigna radiata L.). Siderophores were extracted and purified using Amberlite XAD-4 and applied to plants at concentrations of 5, 10, and 15 µg/mL, followed by pathogen inoculation. The treatments significantly influenced enzymatic activities and defense-related gene expression. On Day 6, peroxidase (POD) activity reached its highest value of 0.563 in the SP15 (siderophore + pathogen at 15 µg/mL) treatment, with S15 (siderophore-only at 15 µg/mL) showing a lower but significant increase of 0.453, while control groups remained unchanged. Polyphenol oxidase (PPO) activity peaked in SP15 (0.10 U/mL), followed by S15 (0.08 U/mL), highlighting the role of these treatments in enhancing stress responses. Chitinase activity was significantly elevated in SP15 on Day 6, with a sustained response through Day 8, while no significant change was observed in the control group. Total phenolic content was highest in SP15 (100 µg/mL), showing a a ramified immune response whereas S15 recorded 80 µg/mL, significantly above the control. Gene expression analysis further demonstrated the effectiveness of siderophore and siderophore + pathogen treatments. Catalase expression was upregulated by 21.1-fold in siderophore-only treatment and amplified to 25.9-fold in SP15. Epoxide hydrolase (EH) gene expression increased by 77.3-fold in S15 and further synergized to over 90-fold in SP15. Similarly, PR10 expression showed moderate upregulation in S15 and significantly higher levels in SP15, reflecting enhanced pathogen defense. Calmodulin (CAL) gene expression was moderately regulated in S15 but significantly amplified in SP15. These findings underscore the dual role of siderophores in nutrient acquisition and as potent elicitors of plant defenses, highlighting their potential as bio-stimulants. Field trials are essential to validate these results under natural conditions and optimize their use in agriculture.

Abstract licence: CC BY

Polyphosphate (polyP) is found in plankton of diverse aquatic ecosystems and is important for plankton ecology and biogeochemical cycling. However, our knowledge of polyP in aquatic environments is hindered by a lack of data due to the limitations of quantification methods. The estimate of polyP in model organisms using phenol-chloroform extraction followed by enzymatic hydrolysis is complicated and fails for environmental samples. The commonly used 4',6-diamidino-2-phenylindole (DAPI) fluorescence method for environmental studies, on the contrary, severely overestimates polyP due to interference. In this paper, we develop a plankton lysis buffer to extract polyP and a quantification method using a novel polyP-specific fluorescence dye JC-D7. We test the methods using cultured algae and bacteria, as well as natural samples from marine and freshwater environments. We show that our plankton lysis extracts polyP with high recovery while requiring substantially less time and effort. Subsequent polyP quantification using JC-D7 fluorescence overcomes the interference encountered by the DAPI method and provides an accurate measurement of polyP down to -1. This novel method enables more accurate quantification of polyP in aquatic environments and will profoundly enhance our knowledge of polyP, plankton ecology, and biogeochemistry.

Abstract licence: CC BY-NC-ND