Marwa Tamim A. Abdel-Wareth

Introduction: Seasonal variation of physicochemical parameters and metal concentrations in water sources can affect the type and density of microorganisms. These microorganisms might include pathogenic bacteria, parasites, and viruses. This study aims to investigate contamination of Nile River water at Greater Cairo sites by examining the type of microbiome, physicochemical characteristics, and heavy metal concentrations. Methods: Nile water samples were seasonally collected and centrifuged, and their total DNA was extracted and amplified by polymerase chain reaction (PCR) for qualitative detection of eubacteria, eukaryotes, and adenoviruses. Heavy metals were analyzed in water samples using an atomic absorption spectrometer. Results: No adenoviruses were detected; 97.92% of the samples were positive for eukaryotes, 93.75% for Gram-positive bacteria, and 6.25% for Gram-negative bacteria. Although iron, cadmium, calcium, and copper concentrations were within permissible limits, lead and zinc exceeded the limits at certain sites, with maxima of 93.4 µg/L and 100 mg/L, respectively. Principal component analysis indicated that eukaryotes and Gram-positive bacteria showed positive correlations with temperature and pH, and negative correlations with Zn, Cd, Ca, and Fe. On the other hand, Gram-negative bacteria were positively correlated with dissolved oxygen, and negatively correlated with temperature, pH, total dissolved solids, and Pb. Conclusion: Nile River water in Greater Cairo may be contaminated with pathogenic bacteria, parasites, and fungi. In addition, the physicochemical characteristics and metal pollution of Nile River water correlated with the microbiome type and density in the investigated sites.

Climate change, reflected in temperature variations, affects various ecosystems, including the freshwater ecosystem, where fungi play major roles in ecological functioning. This study reported an increase of approximately 2°C in water temperature between 2012 and 2019 in waterbodies representing El-Gharbeya Governorate, Egypt. This rise in temperature modified the frequency and composition of waterborne fungal genera. Several genera identified in 2019 had not been detected in samples from 2012. Although fungi contribute to nutrient cycling and the sequestration of xenobiotics, their spread may lead to adverse outcomes. Some fungal strains are known etiological agents of diseases in fish and human beings. Fish production—an important part of the national economy—and public health could therefore be at risk.

Water pollution with pesticides is one of the most important environmental problems. Polychlorinated biphenyls (PCBs) reach water bodies via agricultural discharge. The aim of this study was to determine the contamination of different water bodies with PCB congeners, and detect the correlation between water quality parameters and seasonal distribution of these PCBs. The results indicated that water canals of AlGharbiah showed the highest ranges of temperature, total dissolved solids (TDS) in spring, and dissolved oxygen (DO) in autumn, while AlQaliobiah water bodies witnessed the highest pH and electrical conductivity (EC) ranges in summer. The highest range of a PCB congener was that of PCB44 (7.96-118.29 mu g/g) in sediment samples of Giza, followed by its range (18.01-85.44 mu gL-1) in surface water of AlQaliobiah. We found a potential cancer risk from dermal contact with all the investigated PCBs. Principal component analysis (PCA) showed positive correlations between most PCBs and each of EC and TDS, and a negative correlation with DO. While the correlation between PCBs and each of temperature and pH varied according to the geographic location of the governorate. In conclusion, the investigated water canals were contaminated with PCBs, which posed a potential cancer risk and deteriorated water quality.

Contamination of water and sediment with pyrethroids and triazoles residues can affect fungal diversity, and hence the aquatic system functioning. The aim of the present study is to investigate the effect of water and sediment contamination with pyrethroids and triazoles on fungal diversity. Water and sediment samples were seasonally collected along 2019 from water bodies representing Gharbeya and Qualubeya governorates. Concentrations of pyrethroids and triazoles were determined, and fungal species in water and sediment samples were molecularly identified. The results indicated that temperature and pH varied according to the season. Permethrin, deltamethrin, lambda-cyhalothrin and esfenvalerate showed the highest pyrethroids concentrations, whereas tetraconazole, tebuconazole and difenconazole were of the highest triazoles concentrations. Aspergillus niger was one of the most frequent species, in addition to Trichoderma capillare, Fusarium oxysporum, Penicillium commune and Penicillium polonicum. Principal component analysis indicated a positive correlation between temperature and different Aspergillus spp., and between pH and each of pyrethroids and triazoles. Moreover, a negative correlation was observed between triazoles and Trichoderma asperellum, Penicillium griseofulvum and Aspergillus fumigatus. In conclusion, contamination of water with pesticides affected fungal diversity. This disturbance in fungal assemblages might result in a reduction of some key organisms, or an increase and emergence of new pathogens.

The aim of this study was to evaluate the manganese and nickel biosorption capacities of Jatropha curcas seed husk and its endophyte Aspergillus niger. We found that the optimum concentrations for Mn to be adsorbed by J. curcas seed husk and A. niger dry biomasses were 1.1 and 3.3 mg/L, respectively. For Ni, they were 4.56 and 6.84 mg/L, respectively. The highest biosorption capacities for J. curcas seed husk and A. niger were observed at pH 6 and 8, respectively, for Mn, and 4-8 and 6, respectively, for Ni. The highest removal percentages of Mn by J. curcas seed husk and A. niger biomasses were at 30°C and 40°C, respectively, whereas for Ni, they were 30–60°C, and 50 and 60°C, respectively. Augmentation of both biosorbents resulted in 100% removal of Ni. Fourier transform infrared spectroscopy and scanning electron microscopy verified the bioremediation ability of both biosorbents.

Water quality is one of the most important issues, especially due to the water scarcity that the world is currently facing. Surface water in Egypt is receiving agricultural, industrial, and municipal effluents. The aim of the present study was to investigate the quality of some water canals in Giza and Gharbeya governorates using abiotic and biotic factors. Physicochemical parameters, snail distribution, and frequency of fungal genera were determined from March 2020 to February 2021. The highest water temperatures were recorded during summer and spring in Giza and Gharbeya governorates, respectively, and of electrical conductivity was observed during winter and summer, respectively. Physa acuta snails were the most abundant in all seasons. Also, Aspergillus sp. was the most frequent amongst all identified fungi during all seasons, except winter in Gharbeya Governorate, where Trichoderma sp. was the most frequent. According to the Shannon-Wiener index, autumn showed the highest diversity of snails and fungi in Giza Governorate. For Gharbeya Governorate, snails’ diversity showed the highest equal value in summer and autumn, while that of fungi was in spring. In Giza Governorate, Dissolved oxygen showed a strong positive association with Physa acuta and Aspergillus sp. In Gharbeya Governorate, temperature, electrical conductivity, and total dissolved solids exhibited a strong positive correlation with Aspergillus sp., while they showed negative correlations with Lymnaea natalensis and Bulinus truncatus snails. The relationships between fungal genera and snail species varied according to the governorate. In conclusion, low water quality and global warming might result in a decrease of schistosomiasis and fascioliasis dissemination but also can lead to the incidence of more fungal diseases.

Sir,Biomphalaria alexandrina snails that act as the intermediate hosts of Schistosoma mansoni are normal fauna of freshwater systems in Egypt. They were not introduced to these waters by any means,...