We have cloned DNA fragments of plasmid pFL40 from Alcaligenes xylosoxidans ssp. denitrificans ABIV encoding a D,L-2-haloalkanoic acid halidohydrolase (DhlIV). A 6.5-kb EcoRI/SalI-fragment with inducible expression of the halidohydrolase was cloned in Pseudomonas fluorescens and Escherichia coli. A 1.9-kb HindII-fragment demonstrated expression of the dehalogenase only due to the presence of the promoter from the pUC vector in Escherichia coli. The nucleotide sequence of this DNA-fragment was determined. It had an open reading frame coding for 296 amino acid residues (molecular weight of 32783 D). The dhlIV gene showed sequence homology to a short segment of a D-specific dehalogenase (hadD) from Pseudomonas putida AJ1, but not to any other known DNA sequences. Restriction enzyme patterns indicated similarity between dhlIV and the D,L- isomer specific dehl dehalogenase gene from Pseudomonas putida PP3. There are some indications from restriction enzyme patterns and initial sequencing data, that a gene encoding a sigma 54-dependent activator protein, similar to the dehRI regulatory gene from Pseudomonas putida PP3 is located upstream of dhlIV. In contrast to DehI, dehalogenation of D- or L-chloropropionic acid by the DhlIV-protein leads to lactic acid of inverted configuration.
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Nanoscale Adv
January 2025
Department of Chemistry, School of Sciences & Engineering, The American University in Cairo AUC Avenue, P.O. Box 74 New Cairo 11835 Egypt +202 2615 2559.
Biofilms formed by several bacterial strains still pose a significant challenge to healthcare due to their resistance to conventional treatment approaches, including antibiotics. This study explores the potential of loading natural extracts with antimicrobial activities into β-cyclodextrin (βCD) nanoparticles, which are FDA-approved and have superior biocompatibility owing to their cyclic sugar structures, for biofilm eradication. An inclusion complex of βCD carrying essential oils (BOS) was prepared and characterized with regard to its physicochemical properties, antimicrobial efficacy, and antibiofilm activities.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
Key Laboratory of Sustainable Utilization of Panax Notoginseng Resources of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan 650500, China.
The extensive agricultural use of the fungicide difenoconazole (DIF) and its associated toxicity increasingly damage ecosystems and human health. Thus, an urgent need is to develop environmentally friendly technological approaches capable of effectively removing DIF residues. In this study, strain A-3 was isolated for the first time which can degrade DIF efficiently.
View Article and Find Full Text PDFLangmuir
January 2025
ESYCOM, CNRS-UMR 9007, Université Gustave Eiffel, F-77454 Marne-la-Vallée, France.
This study investigates the synthesis, characterization, and functional properties of well-aligned zinc oxide (ZnO) nanowires (NWs) obtained by a two-step hydrothermal method. ZnO NWs were grown on silicon substrates precoated with a ZnO seed layer. The growth process was conducted at 90 °C for different durations (2, 3, and 4 h) to examine the time-dependent evolution of the nanowire properties.
View Article and Find Full Text PDFBiochem J
January 2025
School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia.
The sulfosugar sulfoquinovose (SQ) is catabolized through the sulfoglycolytic Entner-Doudoroff pathway, beginning with the oxidation of SQ to sulfogluconolactone by SQ dehydrogenase. We present a comprehensive structural and kinetic characterization of Pseudomonas putida SQ dehydrogenase (PpSQDH). PpSQDH is a tetrameric enzyme belonging to the short-chain dehydrogenase/reductase (SDR) superfamily with a strong preference for NAD+ over NADP+.
View Article and Find Full Text PDFJ Biol Eng
January 2025
Synthetic Biology Research Center and the K-Biofoundry, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 34141, Republic of Korea.
Background: As our understanding of gut microbiota's metabolic impacts on health grows, the interest in engineered probiotics has intensified. This study aimed to engineer the probiotic Escherichia coli Nissle 1917 (EcN) to produce indoleacetic acid (IAA) in response to gut inflammatory biomarkers thiosulfate and nitrate.
Results: Genetic circuits were developed to initiate IAA synthesis upon detecting inflammatory signals, optimizing a heterologous IAA biosynthetic pathway, and incorporating a RiboJ insulator to enhance IAA production.
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