Search

The inequality between available water supplies and growing water demand from diverse sectors, as well as the predicted climate changes are putting significant pressures on Egypt's food security. There is a nation-wide demand for new scientifically proven on-farm practices to boost water productivity of major food crops. The objective of this study was to explore the use of various deficit irrigation schemes to improve water productivity (WP) of tomato cultivated in Egypt under distinct climate change scenarios, RCP4.5 and RCP8.5, in three time-steps of the reference period (2006-2016), 2030s, and 2050s. The AquaCrop model was used to simulate the influence of climate change on the tomato crop, as well as two deficit irrigation application schemes for the full growing season and the regulated application for the initial and maturity crop stages. With the same irrigation method, the predicted WP increased in a general pattern across all climate change scenarios. The combination of irrigation schedule with the 80% deficit irrigation can enhance WP near the optimum level (approximately 2.2 kg·m-3), especially during early and mature stages of the crop, saving up to 16% of water. The results showed that the expected temperature rise by 2050s would reduce the crop growth cycle by 3-11 days for all irrigation treatments, resulting in a 1-6% decrease in crop evapotranspiration (ETc) and affecting the dry tomato yield with different patterns of increase and decrease due to climate change. [ABSTRACT FROM AUTHOR]

Pisolithus albus (Basidiomycota, Sclerodermataceae) is reported here for the first time from Egypt where it was found on the Karaman Island in Sohag Governorate. It was found forming an ectomycorrhizal association with Eucalyptus occidentalis and Vachellia nilotica. The fungus was also reported near two potentially new hosts: Paspalum distichum and Dodonaea viscosa; however, the mycorrhizal connections with these two hosts is not proven. Phylogenetic analyses for the combined ITS and LSU rDNA sequences dataset placed the Egyptian specimen within the Pisolithus albus complex clade. It is described, illustrated, and phylogenetically analyzed in this article. Various hosts and locations of the taxon are reviewed. [ABSTRACT FROM AUTHOR]

Annulatascus nilensis sp. nov., from freshwater habitats in Egypt, is described, illustrated and compared,to other species in the genus. Phylogenetic analyses of its LSU rDNA sequence with similar fungi placed the new,species in the genus Annulatascus (Annulatascaceae, Sordariomycetidae incertae sedis). Annulatascus nilensis is,characterized by immersed ascomata with an ascomatal neck oriented horizontally to the substrate surface, asci,with a long, narrow stalk and massive bipartite apical ring, and 5-11-septate, hyaline ascospores surrounded by a,large irregular, granular sheath that is not seen in water. [ABSTRACT FROM AUTHOR]

The concentrations of six heavy metals (Fe, Mn, Ni, Cu, Pb and Zn) were studied in 11 hard and 4 soft common coral species collected from Hurghada, Wadi Al-Gemal and Gola’an along the Red Sea coast to assess the differential abilities of corals to concentrate and assimilate the heavy metals inside soft coral tissues and hard coral skeletons. These results reveal the order of Fe > Zn > Ni > Pb ≥ Mn > Cu. Fe recorded significant high concentrations in mushroom (funnel) forms of the soft corals at the different sites; 125.19, 101.71 and 90.44 ppm at Gola’an, Hurghada and Wadi Al-Gemal, respectively. The soft coral species recorded the highest average concentration of Mn, Ni, Cu and Zn than the hard corals, which were 13.22, 16.05, 13.08 and 148.17 ppm, respectively. Generally, soft corals show higher metal concentrations than the hard ones; moreover, Hurghada recorded a higher trend of metal concentrations in soft and hard corals than the other sites. The study concluded that many biological and local environmental factors influenced the metal occurrences and uptakes in both coral forms such as, the exposed surface area for metal uptake, turbidity, overlying mucus thickness and the ability of metals to substitute inside the crystal lattice of the hard corals. [ABSTRACT FROM AUTHOR]

The increasing mandate for fresh-like food products and the possible hazards of chemically preserved foods necessitate the search for alternatives. Bacteriocins represent a promising food biopreservative. In the present study, one hundred enterococci isolates recovered from Egyptian raw cow milk and homemade dairy products were screened for bacteriocin production. The overall detection rate was 10%. Three isolates, namely, Enterococcus faecalis (OE-7 and OE-12) and Enterococcus hirae (OE-9), showed the highest antibacterial activity with narrow spectrum against multidrug-resistant (MDR) Gram-positive foodborne bacteria: Enterococcus faecalis and Staphylococcus aureus. The antimicrobial activity was completely abolished by trypsin and proteinase K but not affected by lipase and/or amylase indicating the protein nature of the antimicrobial activity. Optimum conditions for bacteriocin production were cultivation in MRS broth at 37 °C, pH 6-6.5 for 16-24 h. The tested bacteriocins exhibited bactericidal activity on S. aureus subsp. aureus ATCC 25923; such activity was further investigated by transmission electron microscopy that revealed leakage and lysis of treated cells. Characterization of tested bacteriocins revealed high activity in a wide range of pH and temperature, storage stability, and heat resistance. PCR analysis revealed that the tested isolates produced multiple enterocins showing homology with the enterocins L50A, AS-48, and 31. Finally, this study reported potent antibacterial activity of bacteriocins derived from dairy products Enterococci against MDR foodborne and spoilage pathogens. The potency, specificity, and stability of these bacteriocins presented promising perspectives for application as biopreservatives in the food industry. The biopreservation of foods by bacteriocins produced by lactic acid bacteria recovered directly from foods remains an innovative approach.