To investigate the nitrite reducing activity of microperoxidases (mps) in the presence of methyl viologen and dithionite, the fragments C14-K22 (mp9), V11-L32 (mp22), and G1-M65 (mp65) containing heme were prepared by enzymatic hydrolysis of commercially equine heart cytochrome c (Cyt c), in which His is axially coordinated to heme iron, and acts as its fifth ligand. The nitrite reducing activity of mps was measured under anaerobic condition, and the nitrite reducing activity of mps increased with the cutting of the peptide chain. The activity of the shortest nonapeptide mp9 was approximately 120-fold that of Cyt c (104 amino acid residues) and 3.2-fold that of nitrite reductase (EC 1.7.7.1) from Escherichia coli. In the nitrite reduction by mp, nitrite was completely reduced to ammonia. We presumed that ferrous mps reduced NO2- to NO by donating one electron, the NO was completely reduced to NH4+ under anaerobic condition via ferrous-NO complexes as a reaction intermediate using visible spectra and ESR spectra, and this overall reaction was a 6-electron and 8-proton reduction. Sepharose-immobilized mp9 had a nitrite reducing activity similar to that of mp9 in solution, and the resin retained the activity after five uses and even 1-year storage. The mp will be able to use as a substitute for nitrite reductase.
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http://dx.doi.org/10.1016/j.bbrc.2004.01.133 | DOI Listing |
Front Pharmacol
December 2024
Department of Biochemistry, Quaid-i-Azam University, Islamabad, Pakistan.
Background: The global prevalence of diabetes among adults over 18 years of age is expected to increase from 10.5% to 12.2% (between 2021 and 2045).
View Article and Find Full Text PDFBMC Microbiol
December 2024
TCM (Traditional Chinese Medicine), Huzhou Central Hospital, Key Laboratory Cultivation Base of Zhejiang Province for the Development and Clinical Transformation of Immunomodulatory Drugs, Fifth School of Clinical Medicine of Zhejiang Chinese Medical University, Huzhou, Zhejiang, China.
Background: Saffron (Crocus sativus L.) is a valuable herb. With the increasing demand for saffron, people are starting to focus on how to increase its yields.
View Article and Find Full Text PDFSci Rep
December 2024
Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Falmouth, USA.
Coral reef sponges efficiently take up particulate and dissolved organic matter (DOM) from the water column and release compounds such as nucleosides, amino acids, and other dissolved metabolites to the surrounding reef via their exhalent seawater, but the influence of this process on reef picoplankton and nutrient processing is relatively unexplored. Here we examined the impact of sponge exhalent on the reef picoplankon community and subsequent alterations to the reef dissolved metabolite pool. We exposed reef picoplankton communities to a sponge exhalent water mixture (Niphates digitalis and Xestospongia muta) or filtered reef seawater (control) in closed, container-based dark incubations.
View Article and Find Full Text PDFBioresour Technol
December 2024
Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, 210094, China; Engineering Research Centre of Chemical Pollution Control, Ministry of Education, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, 210094, China. Electronic address:
Anammox coupled partial S-driven autotrophic denitrification (PSAD) technology represents an innovative approach for removing nitrogen from wastewater. The research highlighted the crucial role of biofilm on sulfur particles in the nitrogen removal process. Further analysis revealed that sulfur-oxidizing bacteria (SOB) are primarily distributed in the inner layer of the biofilm, while anammox bacteria (AnAOB) are relatively evenly distributed in inner and outer layers, with Thiobacillus and Candidatus Brocadia being the dominant species, respectively.
View Article and Find Full Text PDFFront Microbiol
December 2024
College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, China.
Sour meat is a popular traditional fermented product and is a rich source of novel strains with probiotic potential. In this study, we aimed to assess the probiotic potential of lactic acid bacteria (LAB) strains isolated from fermented sour meat. Firstly, the microbial diversity of sour meat from four different areas in China was analyzed.
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