Abstract: The antimicrobial activity of donkey milk was examined against 3 bacterial and 3 fungal strains selected on the basis of their relevance as human pathogens. All samples of donkey milk exhibited antimicrobial activity against dermatomycotic fungi and foodborne pathogen bacteria. The highest antimicrobial activity was recorded against Trichophyton mentagrophytes and T. rubrum with minimal lethal concentration of 32 mg/ml. In respect to foodborne pathogenic bacteria, Gram- positive bacteria (Bacillus cereus and Staphylococcus aureus) were more sensitive to donkey milk than Gram-negative bacteria (E. coli) with minimal lethal concentrations of 32, 64 and 128 mg/ml respectively. Donkey milk kept about 60 to 62% of its antimicrobial activity against B. cereus and S. aurous respectively, after digestion with pepsin (2 mg/ml), suggesting that the fatty acids of donkey milk has the highest antimicrobial effect. While the antimicrobial activity against dermatomycotic fungi and Gram-negative bacteria not affected after digestion with pepsin. To explain the antifungal capability of donkey milk against dermatomycotic fungi, fatty acids were analyzed by gas chromatography. Fatty acids analysis indicated that the major constituents in donkey milk lipid are oleic (25.4%), palmitic (23.75%), linolenic (20.04%), arachidic (3.58%) and stearic (3.26%), which have antimicrobial activity. Finally, on the basis of results obtained in the current study, the antimicrobial activity of donkey milk against Staphylococcus aureus and dermatomycotic fungi, specially T. mentagrophytes and T. rubrum which frequently cause acute or chronic inflammatory tinea corporis; may be considered as a valuable natural product with novel functional protection properties in cosmetics and pharmaceutical industries.

ABSTRACT Forty isolates of the most commonly encountered fungal species from different extreme habitats of Wadi El-Natrun region were tested for their capabilities of producing cellulase, xylanase and pectinase enzymes. Most of these isolates had the capabilities of producing cellulase (95% of the isolates), but with different degrees; however only 3 out of 20 isolates tested were xylanolytic (15%) and one out of 39 was pectinolytic. Eleven strains showed high producing abilities of cellulase and only 2 of xylanase on different screening media. Of the high cellulase producers: some produced cellulase on one medium only e.g. the control medium (Alternaria alternata), medium adjusted at pH 4 (Aspergillus terreus, Cladosporium cladosporioides) or medium supplemented with 10% NaCl (Emericella nidulans, Fusarium solani, Cochliobolus australiensis). Others produced cellulase on the control, 10% NaCl and the acidic media (Emericella nidulans) or on control, 10% NaCl and alkaline media (Cladosporium cladosporioides). Some isolates produced cellulase on both the control, acidic, alkaline and NaCl media (Emericella nidulans). The highly xylanolytic activities were demonstrated only by Emericella nidulan isolates. Finally, the present results reveal some very interesting isolates having the high capabilities for producing more than one enzyme on more than one of the screening media.

ABSTRACT Forty isolates of the most commonly encountered fungal species from different extreme habitats of Wadi El-Natrun region were tested for their capabilities of producing cellulase, xylanase and pectinase enzymes. Most of these isolates had the capabilities of producing cellulase (95% of the isolates), but with different degrees; however only 3 out of 20 isolates tested were xylanolytic (15%) and one out of 39 was pectinolytic. Eleven strains showed high producing abilities of cellulase and only 2 of xylanase on different screening media. Of the high cellulase producers: some produced cellulase on one medium only e.g. the control medium (Alternaria alternata), medium adjusted at pH 4 (Aspergillus terreus, Cladosporium cladosporioides) or medium supplemented with 10% NaCl (Emericella nidulans, Fusarium solani, Cochliobolus australiensis). Others produced cellulase on the control, 10% NaCl and the acidic media (Emericella nidulans) or on control, 10% NaCl and alkaline media (Cladosporium cladosporioides). Some isolates produced cellulase on both the control, acidic, alkaline and NaCl media (Emericella nidulans). The highly xylanolytic activities were demonstrated only by Emericella nidulan isolates. Finally, the present results reveal some very interesting isolates having the high capabilities for producing more than one enzyme on more than one of the screening media.

ABSTRACT Thirty-nine isolates of the most commonly encountered fungal species from different extreme habitats of Wadi El-Natrun region were tested for their capabilities of producing protease, lipase and phosphatase enzymes. Most of these isolates had the capabilities of producing protease (84.2%), lipase (89.7%) and phosphatase (100%) but with different degrees. Thirty-five isolates showed high producing abilities of phosphatase (30 isolates), lipase (22) and protease (8) on different screening media. Some of these isolates were high producers for more than one enzyme, on one or more of the screening media. The present results reveal some very interesting strains having the high capabilities for producing more than one enzyme on more than one of the screening. media.

ABSTRACT Thirty-nine isolates of the most commonly encountered fungal species from different extreme habitats of Wadi El-Natrun region were tested for their capabilities of producing protease, lipase and phosphatase enzymes. Most of these isolates had the capabilities of producing protease (84.2%), lipase (89.7%) and phosphatase (100%) but with different degrees. Thirty-five isolates showed high producing abilities of phosphatase (30 isolates), lipase (22) and protease (8) on different screening media. Some of these isolates were high producers for more than one enzyme, on one or more of the screening media. The present results reveal some very interesting strains having the high capabilities for producing more than one enzyme on more than one of the screening. media.

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The fresh and dry weight of roots and shoots of wheat seedlings showed a marked decrease as the concentration of copper (Cu) was increased. The contents of pectin, cellulose, soluble carbohydrates, and phospholipids in the roots and shoots of test plants were significantly lowered with the rise of Cu concentration. However, hemicellulose, lignin, total lipids, glycolipids, sterols and proline of roots and shoots were raised under Cu stress. Cu treatment also induced the stimulation of soluble, total and cell wall associated proteins, other free amino acids and total carbohydrates in shoots and a slight reduction in roots. The adverse effects of Cu toxicity treatments on root and shoot growth were partially alleviated by the treatment of test plants with ascorbic acid, thiamine (vitamin B1) and salicylic acid.

Introduction: Toxic soil concentrations of the essential micronutrient boron (B) represent major limitations to crop production worldwide. Plants have a range of defense systems that might be involved in their affinity to resist and tolerate nutrients stress. Materials and methods: The experiments were carried out to study the differential responses in five wheat cultivars to boron toxicity. Results: The fresh and dry matter yield of the test wheat cultivars showed marked decrease as the concentration of boron was increased. Elevated concentration of boron had a notable inhibitory effect on the biosynthesis of pigments fractions in the test wheat cultivars as severely as dry matter gain. The adverse concentration effects of boron on some metabolic responses were clearly displayed by shoot and root systems, exhibited in the elevated rates of proline, hydrogen peroxide and malondialdehyde formation. Potassium leakage was severely affected by boron-stress in some cultivars at all tested concentrations, while in some others a moderate damage was manifested only at the higher boron concentrations. Conclusions: Sakha 93 out of all the different cultivars investigated was found to display the lowest sensitivity to boron-stress, while Gemmeza 9 was the most sensitive one.

Introduction: Toxic soil concentrations of the essential micronutrient boron (B) represent major limitations to crop production worldwide. Plants have a range of defense systems that might be involved in their affinity to resist and tolerate nutrients stress. Materials and methods: The experiments were carried out to study the differential responses in five wheat cultivars to boron toxicity. Results: The fresh and dry matter yield of the test wheat cultivars showed marked decrease as the concentration of boron was increased. Elevated concentration of boron had a notable inhibitory effect on the biosynthesis of pigments fractions in the test wheat cultivars as severely as dry matter gain. The adverse concentration effects of boron on some metabolic responses were clearly displayed by shoot and root systems, exhibited in the elevated rates of proline, hydrogen peroxide and malondialdehyde formation. Potassium leakage was severely affected by boron-stress in some cultivars at all tested concentrations, while in some others a moderate damage was manifested only at the higher boron concentrations. Conclusions: Sakha 93 out of all the different cultivars investigated was found to display the lowest sensitivity to boron-stress, while Gemmeza 9 was the most sensitive one.