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Data from the Gravity Recovery and Climate Experiment (GRACE) and outputs of the CLM4.5 model were used to estimate recharge and depletion rates for large aquifers, investigate the connectivity of an aquifer’s subbasins, and identify barriers and preferred pathways for groundwater flow within an aquifer system. The Nubian Sandstone Aquifer System and its subbasins (Dakhla, Northern Sudan Platform, and Kufra) in northeast Africa were used for demonstration purposes, and findings were tested and verified against geological, geophysical, remote sensing, geochronologic, and geochemical data. There are four major findings. (1) The average annual precipitation data over recharge areas in the southern Kufra section and the Northern Sudan Platform subbasin were estimated at 54.8 km3, and 32.8 km3, respectively, and knowing the annual extraction rates over these two areas (~0.40 ± 0.20 km3), recharge rates were estimated at 0.78 ± 0.49 km3/yr and 1.44 ± 0.42 km3/yr, respectively. (2) GRACEderived groundwater depletion rates over the Dakhla subbasin and the Northern Kufra section were estimated at 4.44 ± 0.42 km3/yr and 0.48 ± 0.32 km3/yr, respectively. (3) The observed depletion in the southern parts of the Dakhla subbasin is apparently caused by the presence of the east-west–trending Uweinat-Aswan basement uplift, which impedes the south-to-north groundwater flow and hence reduces replenishment from recharge areas in the south. (4) A major northeast- southwest–trending shear zone (Pelusium shear system) is apparently providing a preferred groundwater flow pathway from the Kufra to the Dakhla subbasin. Our integrated approach provides a replicable and cost-effective model for better understanding of the hydrogeologic setting of large aquifers worldwide and for optimum management of these groundwater resources.

Data from the Gravity Recovery and Climate Experiment (GRACE) and outputs of the CLM4.5 model were used to estimate recharge and depletion rates for large aquifers, investigate the connectivity of an aquifer’s subbasins, and identify barriers and preferred pathways for groundwater flow within an aquifer system. The Nubian Sandstone Aquifer System and its subbasins (Dakhla, Northern Sudan Platform, and Kufra) in northeast Africa were used for demonstration purposes, and findings were tested and verified against geological, geophysical, remote sensing, geochronologic, and geochemical data. There are four major findings. (1) The average annual precipitation data over recharge areas in the southern Kufra section and the Northern Sudan Platform subbasin were estimated at 54.8 km3, and 32.8 km3, respectively, and knowing the annual extraction rates over these two areas (~0.40 ± 0.20 km3), recharge rates were estimated at 0.78 ± 0.49 km3/yr and 1.44 ± 0.42 km3/yr, respectively. (2) GRACEderived groundwater depletion rates over the Dakhla subbasin and the Northern Kufra section were estimated at 4.44 ± 0.42 km3/yr and 0.48 ± 0.32 km3/yr, respectively. (3) The observed depletion in the southern parts of the Dakhla subbasin is apparently caused by the presence of the east-west–trending Uweinat-Aswan basement uplift, which impedes the south-to-north groundwater flow and hence reduces replenishment from recharge areas in the south. (4) A major northeast- southwest–trending shear zone (Pelusium shear system) is apparently providing a preferred groundwater flow pathway from the Kufra to the Dakhla subbasin. Our integrated approach provides a replicable and cost-effective model for better understanding of the hydrogeologic setting of large aquifers worldwide and for optimum management of these groundwater resources.

ABSTRACT The chemical and physical techniques applied for nanoparticles synthesis are mostly high cost and may have harmful effects. So, there is an indigence to synthesize a low cost, high yield, most effective and most stable nanoparticles. The antimicrobial activity of mycosynthesized titanium oxide (TiO2NPs) and silver (AgNPs) nanoparticles from mycelial extract of Penicillium chrysogenum AUMC 6092 was the main target of this study. The antimicrobial activity was assayed against 5 pathogenic Gram- positive (Staphylococcus aureus and Streptococcus sp.) and Gram- negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa) bacteria. In addition, 12 human pathogenic fungal strains including some multidrug resistant yeast strains and dermatophytic fungal strains (Epidermophyton floccosum, Microsporum canis, Trichophyton mentagrophytes and T. rubrum) were tested. TiO2NPs and AgNPs synthesized from culture filtrate of Penicillium chrysogenum AUMC 6092 are uniform, spherical and small. The results showed that, generally TiO2NPs and AgNPs had high inhibitory activity against most tested microorganisms, especially when mixed with Tioconazole. TiO2NP2 had the highest inhibitory effect against C. glabrata AUMC 13382, followed by Escherichia coli, Staphylococcus aureus and C. tropicalis AUMC 13378. On the other hand, Staphylococcus aureus and C. glabrata AUMC 13382 were the most sensitive microbial strains towards AgNPs.

ABSTRACT The chemical and physical techniques applied for nanoparticles synthesis are mostly high cost and may have harmful effects. So, there is an indigence to synthesize a low cost, high yield, most effective and most stable nanoparticles. The antimicrobial activity of mycosynthesized titanium oxide (TiO2NPs) and silver (AgNPs) nanoparticles from mycelial extract of Penicillium chrysogenum AUMC 6092 was the main target of this study. The antimicrobial activity was assayed against 5 pathogenic Gram- positive (Staphylococcus aureus and Streptococcus sp.) and Gram- negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa) bacteria. In addition, 12 human pathogenic fungal strains including some multidrug resistant yeast strains and dermatophytic fungal strains (Epidermophyton floccosum, Microsporum canis, Trichophyton mentagrophytes and T. rubrum) were tested. TiO2NPs and AgNPs synthesized from culture filtrate of Penicillium chrysogenum AUMC 6092 are uniform, spherical and small. The results showed that, generally TiO2NPs and AgNPs had high inhibitory activity against most tested microorganisms, especially when mixed with Tioconazole. TiO2NP2 had the highest inhibitory effect against C. glabrata AUMC 13382, followed by Escherichia coli, Staphylococcus aureus and C. tropicalis AUMC 13378. On the other hand, Staphylococcus aureus and C. glabrata AUMC 13382 were the most sensitive microbial strains towards AgNPs.

Abstract: Background: The presence of anthraquinone (Disperse blue 64) and azodyes (Acid yellow 17) in a waterbody are considered among the most dangerous pollutants. Methods: In this study, two different isolated microbes, bacterium and fungus, were individually and as a co-culture applied for the degradation of Disperse Blue 64 (DB 64) and Acid Yellow 17 (AY 17) dyes. The isolates were genetically identified based upon 16S (for bacteria) and ITS/5.8S (for fungus) rRNA genes sequences as Pseudomoans aeruginosa and Aspergillus flavus, respectively. Results: The fungal/bacterial consortium exhibited a higher percentage of dyes degradation than the individual strains, even at a high concentration of 300 mg/L. Azoreductase could be identified as the main catabolic enzyme and the consortium could induce azoreductase enzyme in the presence of both dyes. However, the specific substrate which achieved the highest azoreductase specific activity was Methyl red (MR) (3.5 U/mg protein). The tentatively proposed metabolites that were detected by HPLC/MS suggested that the reduction process catalyzed the degradation of dyes. The metabolites produced by the action consortium on two dyes were safe on Vicia faba and Triticum vulgaris germination and health of seedlings. Toxicity of the dyes and their degradation products on the plant was different according to the type and chemistry of these compounds as well as the type of irrigated seeds. Conclusion: We submit that the effective microbial degradation of DB64 and AY17 dyes will lead to safer metabolic products.

Abstract: Background: The presence of anthraquinone (Disperse blue 64) and azodyes (Acid yellow 17) in a waterbody are considered among the most dangerous pollutants. Methods: In this study, two different isolated microbes, bacterium and fungus, were individually and as a co-culture applied for the degradation of Disperse Blue 64 (DB 64) and Acid Yellow 17 (AY 17) dyes. The isolates were genetically identified based upon 16S (for bacteria) and ITS/5.8S (for fungus) rRNA genes sequences as Pseudomoans aeruginosa and Aspergillus flavus, respectively. Results: The fungal/bacterial consortium exhibited a higher percentage of dyes degradation than the individual strains, even at a high concentration of 300 mg/L. Azoreductase could be identified as the main catabolic enzyme and the consortium could induce azoreductase enzyme in the presence of both dyes. However, the specific substrate which achieved the highest azoreductase specific activity was Methyl red (MR) (3.5 U/mg protein). The tentatively proposed metabolites that were detected by HPLC/MS suggested that the reduction process catalyzed the degradation of dyes. The metabolites produced by the action consortium on two dyes were safe on Vicia faba and Triticum vulgaris germination and health of seedlings. Toxicity of the dyes and their degradation products on the plant was different according to the type and chemistry of these compounds as well as the type of irrigated seeds. Conclusion: We submit that the effective microbial degradation of DB64 and AY17 dyes will lead to safer metabolic products.

Abstract: Background: The presence of anthraquinone (Disperse blue 64) and azodyes (Acid yellow 17) in a waterbody are considered among the most dangerous pollutants. Methods: In this study, two different isolated microbes, bacterium and fungus, were individually and as a co-culture applied for the degradation of Disperse Blue 64 (DB 64) and Acid Yellow 17 (AY 17) dyes. The isolates were genetically identified based upon 16S (for bacteria) and ITS/5.8S (for fungus) rRNA genes sequences as Pseudomoans aeruginosa and Aspergillus flavus, respectively. Results: The fungal/bacterial consortium exhibited a higher percentage of dyes degradation than the individual strains, even at a high concentration of 300 mg/L. Azoreductase could be identified as the main catabolic enzyme and the consortium could induce azoreductase enzyme in the presence of both dyes. However, the specific substrate which achieved the highest azoreductase specific activity was Methyl red (MR) (3.5 U/mg protein). The tentatively proposed metabolites that were detected by HPLC/MS suggested that the reduction process catalyzed the degradation of dyes. The metabolites produced by the action consortium on two dyes were safe on Vicia faba and Triticum vulgaris germination and health of seedlings. Toxicity of the dyes and their degradation products on the plant was different according to the type and chemistry of these compounds as well as the type of irrigated seeds. Conclusion: We submit that the effective microbial degradation of DB64 and AY17 dyes will lead to safer metabolic products.