Publications by authors named "Ahmed A Ismaiel"

Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus spp. and Penicillium spp. that causes a threat to food safety and human health.

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Aims: Contamination with heavy metal (HM) is a severe environmental issue. Therefore, there is a pressing need to create environmentally safe and cost-effective HM bioremediation approaches.

Methods And Results: Three iron-tolerant fungal strains were isolated from sewage-irrigated soils, molecularly identified and deposited in the GenBank as Aspergillus flavus MT639638, A.

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Kombucha is a traditional beverage of sweetened black tea fermented with a symbiotic association of acetic acid bacteria and yeasts. In this study, kombucha fermented beverage (KFB) appeared to include nine chemical groups (alcohols, acids, lactones, condensed heterocyclic compounds, antibiotics, esters, aldehydes, fatty acids, and alkaloids) of many bioactive metabolites, as elucidated by gas chromatography-mass spectrometry (GC-MS) and IR spectra. The fermented metabolic components of KFB seem collectively to act in a synergistic action giving rise to the antimicrobial activity.

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Kefir beverage (KB) is a fermented milk initiated by kefir grains rich with starter probiotics. The KB produced in this study seemed to contain many chemical compounds elucidated by gas chromatography-mass spectrometry (GC-MS) and IR spectra. These compounds could be classified into different chemical groups such as alcohols, phenols, esters, fatty esters, unsaturated fatty esters, steroids, polyalkenes, heterocyclic compounds and aromatic aldehydes.

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Taxol, a phyto-extracted diterpenoid, is the most commercially needed drug in cancer chemotherapy. In spite of the microbial production of taxol being successful and prospective, the reported yields are still not sufficient for large-scale production. Thus, the discovery of new taxol-producing microbial strains and production enhancement methodologies such as process optimization, strain improvement, and immobilization technique are the main objectives.

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The most popular and economically important traditional dairy products in Egypt are raw milk, Karish cheese (an Arabian dairy product made from defatted cow milk) and Zabady (an Arabian yoghurt made from buffalo and cow milk). In this study, 302 traditional dairy samples including raw milk (120), white Karish cheese (118), and Zabady (64) were analyzed for aflatoxin M1 (AFM1) during different seasons in 2016 and 2017. Contamination of raw milk samples with AFM1 was 21.

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Taxol is the most profitable drug ever developed in cancer chemotherapy; however, the market demand for the drug greatly exceeds the supply that can be sustained from its natural sources. In this study, Aspergillus fumigatus TXD105-GM6 and Alternaria tenuissima TER995-GM3 were immobilized in calcium alginate beads and used for the production of taxol in shake flask cultures. In an effort to increase the taxol magnitude, immobilization conditions were optimized by response surface methodology program (RSM).

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UV and gamma irradiation mutagenesis was applied on Aspergillus fumigatus and Alternaria tenuissima in order to improve their producing ability of paclitaxel. Among the screened mutants, two stable strains (designated TXD105-GM6 and TER995-GM3) showed the maximum paclitaxel production. Paclitaxel titers of the two respective mutants were dramatically intensified to 1.

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The mycotoxin patulin (PAT) was purified from CM1 culture that has been isolated from a soil cultivated with maize. The effect of PAT and of a fungal culture filtrate on the activities of glutathione-S-transferase (GST) and some antioxidant enzymes viz. ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR) and monodehydroascorbate reductase (MDHAR) was investigated in roots and shoots of 8-day-old maize seedlings.

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Among 60 fungal endophytes isolated from twigs, bark, and mature leaves of different plant species, two fungal isolates named TXD105 and TER995 were capable of producing paclitaxel in amounts of up to 84.41 and 37.92 μg L, respectively.

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Cyclosporin A (CyA) has received meticulous attention owing to its immunosuppressive and biological activities. In this study, a soil isolate, capable of producing CyA, was named Zag1 strain and identified as Aspergillus fumigatus based on macroscopic and microscopic characteristics, 18S rDNA sequence, and phylogenetic characteristic analysis. To maximize the production of CyA, the fungal culture was grown under various fermentation conditions including selection of the cultivation medium, agitation rate, fermentation time, incubation temperature, pH value, inoculum nature, and medium volume.

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Mycophenolic acid (MPA) is a promising drug owing to its immunosuppressive and biological activities. In this study, two strains of Penicillium roqueforti designated as AG101 and LG109 were selected among several strains isolated from Roquefort cheese samples on the basis of their activity for MPA-producing ability. The appropriate fermentation conditions necessary for MPA biosynthesis by the two respective fungal strains were investigated.

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By using agar well diffusion assay, antifungal activity of aqueous extract prepared from Egyptian garlic (Allium sativum L.) was evaluated in vitro against two strains of Aspergillus flavus (OC1 and OC10) causing human ocular infection. The recorded minimum inhibitory concentration (MIC) for growth inhibition of both strains was 3.

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The association of kefir microbiota was observed by electron microscopic examination. Scanning electron microscopic (SEM) observations revealed that kefir grain surface is very rough and the inner portions had scattered irregular holes on its surface. The interior of the grain comprised fibrillar materials which were interpreted as protein, lipid and a soluble polysaccharide, the kefiran complex that surrounds yeast and bacteria in the grain.

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A suitable chemically defined culture medium was selected and some optimal conditions for the production of the highly immunosuppressive compound, cyclosporin A (Cyc A) are reported. Medium of the following composition was favorable for the production of Cyc A by Fusarium roseum: glucose, 30; NaNO3, 2; KH2PO4, 1; MgSO4.7H2O, 0.

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