Impacts of Anthropogenic Disturbance on Vegetation Dynamics: A Case Study of Wadi Hagul, Eastern Desert, Egypt.

Irresponsible human interventions, encroachment of natural habitats, and climate change negatively affect wildlife. In this study, the effects of human influence on Wadi Hagul, an unprotected area in the north of the Egyptian Eastern Desert that has recently been subjected to blatant encroachments of vegetation, were studied. The most important of these threats is the construction of the new road Al-Galala-Wadi Hagul-Zafarana. In Wadi Hagul, 80 species are reported in this study; the most represented plant families are Asteraceae (15 species) and Brassicaceae (6 species). Perennial, chamaephyte and Saharo-Arabian species were recorded in the highest percentage. Detrended canonical correspondence analysis showed that latitude, longitude, altitude, silt, sand contents, pH, and CO32- content are the factors that have the highest effect on vegetation distribution in the studied stands. Several invasive and alien species such as Euphorbia prostrata have been listed; these species typically have a negative effect on native species. The Soil Adjusted Vegetation Index (SAVI) indicated a decrease in plant cover during the study period, as compared to previous years. In 2013 and 2020, SAVI ranged from -0.02 to 0.42 and from -0.18 to 0.28, respectively. Recently, the violation and destruction of wildlife have increased, therefore, preserving it along with general biodiversity has become an urgent necessity.

Paecilomyces variotii xylanase production, purification and characterization with antioxidant xylo-oligosaccharides production.

Paecilomyces variotii xylanase was, produced in stirred tank bioreactor with yield of 760 U/mL and purified using 70% ammonium sulfate precipitation and ultra-filtration causing 3.29-fold purification with 34.47% activity recovery. The enzyme purity was analyzed on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) confirming its monomeric nature as single band at 32 KDa. Zymography showed xylan hydrolysis activity at the same band. The purified enzyme had optimum activity at 60 °C and pH 5.0. The pH stability range was 5-9 and the temperature stability was up 70 °C. Fe2+and Fe3+ exhibited inhibition of xylanase enzyme while Cu2+, Ca2+, Mg2+ and Mn2+ stimulated its activity. Mercaptoethanol stimulated its activity; however, Na2-EDTA and SDS inhibited its activity. The purified xylanase could hydrolyze beechwood xylan but not carboxymethyl cellulose (CMC), avicel or soluble starch. Paecilomyces variotii xylanase Km and Vmax for beechwood were determined to be 3.33 mg/mL and 5555 U/mg, respectively. The produced xylanase enzyme applied on beech xylan resulted in different types of XOS. The antioxidant activity of xylo-oligosaccharides increased from 15.22 to 70.57% when the extract concentration was increased from 0.1 to 1.5 mg/mL. The enzyme characteristics and kinetic parameters indicated its high efficiency in the hydrolysis of xylan and its potential effectiveness in lignocellulosic hydrolysis and other industrial application. It also suggests the potential of xylanase enzyme for production of XOS from biomass which are useful in food and pharmaceutical industries.

Purification of soybean cupins and comparison of IgE binding with peanut allergens in a population of allergic subjects.

Identification, purification and characterization of allergens is crucial to the understanding of IgE-mediated disease. Immunologic and structural studies with purified allergens is essential for understanding relative immunogenicity and cross-reactivity. In this work, the complex soybean 7S vicilins (Gly m 5) with three subunits and 11S legumins (Gly m 6) with five subunits were purified and characterized along with purified peanut allergens (Ara h 1, 2, 3, and 6) by label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS). Individual subjects plasma IgE binding was tested from subjects allergic to soybeans and or peanuts by immunoblotting, ImmunoCAP™ and ISAC™ ImmunoCAP chip, comparing these soybean proteins with those of purified peanut allergens; vicilin (Ara h 1), 2S albumin (Ara h 2 and Ara h 6) and 11S globulin (Ara h 3). Results show differences between methods and subjects demonstrating the complexity of finding answers to questions of cross-reactivity.