Optimizations of exopolysaccharide production by Fusarium nygamai strain AJTYC1 and its potential applications as an antioxidant, antimicrobial, anticancer, and emulsifier.

BACKGROUND: Exopolysaccharides (EPSs) produced by microbes are recognized as biomacromolecules of great significance. EPSs from fungi are widely used in a variety of biotechnological fields, including medicine, bioremediation, and agriculture. RESULTS: In this study, ten fungal isolates were isolated from Kafir El-Dair, Qalubia Governorate, Egypt. Isolate 5 produced more exopolysaccharides than the other examined fungi. According to microscopic morphological traits and genetic confirmation by the 18S rRNA gene, isolate 5 was identified as Fusarium nygamai strain AJTYC1. The present study showed that Czapek's broth media, which contains 6 g/100 ml of sucrose, 10 g/100 ml of peptone, pH 6, and 1.8 × 105 CFU/ml of inoculum size and is incubated at 30 °C for 9 days, was suitable for the production of EPSs from Fusarium nygamai strain AJTYC1 by using static conditions. Fourier transform infrared (FT-IR) was employed in the characterization of EPSs, which exhibited the presence of carboxyl groups, hydroxyl groups, carbonyl groups, and glycosidic bonds. High-performance liquid chromatography (HPLC) detected that EPSs consist of sucrose and glucose. The scavenging activity indicates that EPSs have good antioxidant activity. The partially purified exopolysaccharides produced from F. nygamai strain AJTYC1 exhibited excellent antioxidant and antimicrobial activity against gram positive, gram negative and fungal strains. The EPSs at a dose of 1000 µg/ml exhibited anticancer activity against colorectal colon cancer (HCT116), breast cancer (MCF7), and hepatocellular cancer cell lines. Moreover, EPSs is an effective emulsifier of a variety of vegetable oils, and the emulsion it produces is generally stable for up to 168 h. CONCLUSIONS: The production of EPSs from F. nygamai strain AJTYC1 can be used as antioxidants, antimicrobials, anticancer, and emulsifiers.

Green synthesized silver nanoparticles mediated by Fusarium nygamai isolate AJTYC1: characterizations, antioxidant, antimicrobial, anticancer, and photocatalytic activities and cytogenetic effects.

Green biosynthesized nanoparticles have a bright future because they can be produced using a method that is more energy-efficient, cost-effective, repeatable, and environmentally friendly than physical or chemical synthesis. In this study, silver nanoparticles (AgNPs) were produced using the Fusarium nygamai isolate AJTYC1. Several techniques were used to characterize the synthesized AgNPs, including UV-Vis spectroscopy, transmission electron microscope, zeta potential analysis, X-ray diffraction analysis, energy dispersive X-ray, and Fourier transform-infrared spectroscopy. AgNPs showed a distinctive surface plasmon resonance (SPR) peak in the UV-visible range at 310 nm. The morphology of the biosynthesized AgNPs was spherical, and the TEM image shows that they ranged in size from 27.3 to 53.1 nm. The notable peaks of the FT-IR results show the different groups for the alkane, alkynes, cyclic alkenes, carboxylic, aromatic amine, esters, and phenolics. Additionally, the results showed that AgNPs had superior antioxidant activity when compared to ascorbic acid and butylated hydroxytoluene, which is a powerful antioxidant. Additionally, AgNPs have antibacterial action utilizing agar diffusion against gram-positive bacteria, gram-negative bacteria, and antifungal activity. AgNPs' anticancer activity varied depending on the type of cancer it was used to treat, including hepatocellular cancer (HepG2), colorectal carcinoma (HCT116), and breast cancer of the mammary gland (MCF7). The viability of the cancer cell lines was reduced with increasing AgNP concentration. AgNPs also demonstrated promising photocatalytic activity by reducing methylene blue, safranin, crystal violet, and green malachite by 88.3%, 81.5%, 76.4%, and 78.2%, respectively. In addition, AgNPs significantly affected the Allium cepa plant's mitotic index and resulted in chromosomal abnormalities as compared to the control. Thus, the synthesized AgNPs demonstrated an efficient, eco-friendly, and sustainable method for decolorizing dyes as well as antioxidant, antibacterial, antifungal, and anticancer activities. This could be a huge victory in the fight against numerous dynamic diseases and lessen wastewater dye contamination.

Pathogenicity of Bacillus Strains to Cotton Seedlings and Their Effects on Some Biochemical Components of the Infected Seedlings.

Pathogenicity of eight Bacillus strains to seedlings of four cotton cultivars was evaluated under greenhouse conditions. Each of the tested cultivars was individually treated with powdered inoculum of each bacterial strain. Untreated seeds were planted as control treatments in autoclaved soil. Effects of the tested strains on levels and activities of some biochemical components of the infected seedlings were also assayed. The biochemical components included total soluble sugars, total soluble proteins, total free amino acids, peroxidase, polyphenol oxidase, phenols, and lipid peroxidation. ANOVA showed that Bacillus strain (B) was a very highly significant source of variation in damping-off and dry weight. Cotton cultivar (V) was a nonsignificant source of variation in damping-off while it was a significant source of variation in dry weight. B × V interaction was a significant source of variation in damping-off and a nonsignificant source of variation in dry weight. Bacillus strain was the most important source of variation as it accounted for 59.36 and 64.99% of the explained (model) variation in damping-off and dry weight, respectively. The lack of significant correlation between levels and activities of the assayed biochemical components and incidence of damping-off clearly demonstrated that these biochemical components were not involved in the pathogenicity of the tested strains. Therefore, it was hypothesized that the pathogenicity of the tested strains could be due to the effect of cell wall degrading enzymes of pathogenic toxins. Based on the results of the present study, Bacillus strains should be considered in studying the etiology of cotton seedling damping-off.

Biosorption effect of Aspergillus niger and Penicillium chrysosporium for Cd- and Pb-contaminated soil and their physiological effects on Vicia faba L.

Phytoremediation is an important solution to soil pollution management. The goal of this study is to determine the biosorption ability of the two selected fungi (Aspergillus niger and Penicillium chrysosporium) under heavy metal stress on faba bean plants. The fungal strains produced phytohormones, siderophore, ACC deaminase, and secondary metabolites. The biosorption capacity of A. niger and P. chrysosporium was 0.09 and 0.06 mg g-1 and 0.5 and 0.4 mg g-1 in media containing Cd and Pb, respectively. Fourier transform infrared spectroscopy of the fungal cell wall show primary functional groups like hydroxyl, amide, carboxyl, phosphoryl, sulfhydryl, and nitro. Therefore, A. niger and P. chrysosporium were inoculated to soils, and then the faba bean seeds were sown. After 21 days of sowing, the plants were irrigated with water to severe as control, with 100 mg L-1 of Cd and 200 mg L-1 of Pb. The results show that Cd and Pb caused a significant reduction in morphological characteristics, auxin, gibberellins, photosynthetic pigments, minerals content, and antioxidant enzymes as compared to control plants but caused a substantial boost in abscisic acid, ethylene, electrolyte leakage, lipid peroxidation, glutathione, proline, superoxide dismutase, secondary metabolites, and antioxidant capacity. In inoculated plants, metal-induced oxidative stress was modulated by inhibiting the transport of metal and decreased electrolyte leakage and lipid peroxidation. Finally, the inoculation of endophytic fungi contributed actively to the absorption of heavy metals and decreased their content in soil and plants. This could be utilized as an excellent technique in the fields of heavy metal-contaminated sustainable agriculture.