Urea, which is known to be a source of nitrogen for the growth of many organisms, represents an important fertilizer in forest soils. Since most trees form symbiotic associations with ectomycorrhizal fungi, the capacities of these symbionts to take up and assimilate urea would determine the efficiency of urea nitrogen salvaging by plants. We showed that Paxillusinvolutus, an ectomycorrhizal basidiomycete, is capable of using urea as sole nitrogen source. We report the molecular characterization of an active urea transporter (PiDur3) isolated from this fungus. We demonstrated that the import of urea is a minor event on ammonium condition, since the expression of PiDUR3 is repressed by the high intracellular glutamine pool. Interestingly, on urea nutritive condition, the uptake of urea is rather mediated by the intracellular urea pool and particularly by urease efficiency.
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http://dx.doi.org/10.1016/j.fgb.2008.01.002 | DOI Listing |
Ann Clin Microbiol Antimicrob
January 2025
Microbiology and Immunology Department, Faculty of Pharmacy, Mansoura University, Mansoura, 35516, Egypt.
Proteus mirabilis (P. mirabilis) is one of the most important causative pathogens associated with complicated urinary tract infections with a 20% incidence. For epidemiological determinations, several phenotypic and molecular typing methods have been implicated.
View Article and Find Full Text PDFMikrochim Acta
January 2025
Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour, 22511, AlBeheira, Egypt.
The hydrothermal synthesis is presented of copper-doped carbon dots (Cu-CDs) from citric acid, urea, and copper chloride, resulting in blue-fluorescent particles with stable emission at 438 nm when excited at 340 nm. Through comprehensive spectroscopic and microscopic characterization (FTIR, XPS, UV, and HRTEM), the Cu-CDs demonstrated remarkable stability across varying pH levels, ionic strengths, temperatures, and UV exposure. Notably, Cu-CDs exhibit ultra-sensitive and selective detection of hexavalent chromium [Cr(VI)] ions in aqueous environments driven by fluorescence quenching.
View Article and Find Full Text PDFEnviron Pollut
January 2025
Department of Plant and Environmental Sciences, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark. Electronic address:
Nitrogen (N) doping of biomass prior pyrolysis has been identified as an effective approach for enhancing biochar catalytic reactivity. However, high-temperature pyrolysis of N-rich biomass may produce N-devoid biochars with high reactivity, calling for attention to the true causes of the reactivity increases and the role of nitrogen. In this study, N-doped wheat straw biochar (N-BC) materials were produced using urea as N dopant and different pyrolysis conditions, and their catalytic reactivity assessed for the reduction of trichloroethylene (TCE) by green rust (GR), a layered Fe(II)Fe(III) hydroxide.
View Article and Find Full Text PDFACS Appl Bio Mater
January 2025
Proteinic and Man-made Fibres Department, Textile Research and Technology Institute, National Research Centre, Cairo, Dokki, 12622, Egypt.
Wool is the most widely used proteinic natural fiber in the clothing industry by virtue of its versatile properties. Unfortunately, wool, as a natural fiber, is more susceptible to attack by microorganisms and moths, which may cause harm to the fiber and human health. That is why the antimicrobial and mothproof finishing of natural textiles is of prime importance to the textile and clothing industry.
View Article and Find Full Text PDFJ Biol Chem
January 2025
Genomics Research Center, Academia Sinica, Taipei, Taiwan; Taiwan International Graduate Program in Interdisciplinary Neuroscience, National Yang Ming Chiao Tung University and Academia Sinica, Taipei, Taiwan; Department of Biochemical Science and Technology, National Taiwan University, Taipei, Taiwan; Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Institute of Biological Chemistry, Academia Sinica; Institute of Biochemical Sciences, National Taiwan University; Taiwan International Graduate Program in Interdisciplinary Neuroscience, National Taiwan University and Academia Sinica, Taipei, Taiwan. Electronic address:
Tauopathies cover a range of neurodegenerative diseases in which natively unfolded tau protein aggregates and spreads in the brain during disease progression. To gain insights into the mechanism of tau structure and spreading, here, we examined the biochemical and cellular properties of human full-length wild-type and familial mutant tau, ΔK280, with a deletion at lysine 280. Our results showed that both wild-type and mutant tau are predominantly monomeric by analytical ultracentrifugation.
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