Whole-cell biocatalysis to oxidize naphthalene to 1-naphthol in liquid-liquid biphasic systems was performed. Escherichia coli expressing TOM-Green, a variant of toluene ortho-monooxygenase (TOM), was used for this oxidation. Three different solvents, dodecane, dioctyl phthalate, and lauryl acetate, were screened for biotransformations in biphasic media. Of the solvents tested, lauryl acetate gave the best results, producing 0.72 +/- 0.03 g/liter 1-naphthol with a productivity of 0.46 +/- 0.02 g/g (dry weight) cells after 48 h. The effects of the organic phase ratio and the naphthalene concentration in the organic phase were investigated. The highest 1-naphthol concentration (1.43 g/liter) and the highest 1-naphthol productivity (0.55 g/g [dry weight] cells) were achieved by optimization of the organic phase. The ability to recycle both free cells and cells immobilized in calcium alginate was tested. Both free and immobilized cells lost more than approximately 60% of their activity after the first run, which could be attributed to product toxicity. On a constant-volume basis, an eightfold improvement in 1-naphthol production was achieved using biphasic media compared to biotransformation in aqueous media.
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http://dx.doi.org/10.1128/AEM.00434-09 | DOI Listing |
Monatsh Chem
December 2023
Institute of Applied Synthetic Chemistry, TU Wien, Vienna, Austria.
Unlabelled: In recent years, sugar alcohols have gained significant attention as organic phase change materials (PCMs) for thermal energy storage due to their comparably high thermal storage densities up to 350 J/g. In a computational study, outstandingly high values of up to ~ 450-500 J/g have been postulated for specific higher-carbon sugar alcohols. These optimized structures feature an even number of carbon atoms in the backbone and a stereochemical configuration in which all hydroxyl groups are in an 1,3--relationship, as found in the natural hexitol d-mannitol.
View Article and Find Full Text PDFChem Sci
December 2024
Department of Chemistry and Biochemistry, University of California, San Diego La Jolla California 92093 USA
Metal-organic frameworks (MOFs) can be prepared from oligomeric organic ligands to prepare materials referred to as oligoMOFs. Studies of oligoMOFs are relatively limited, with most existing reports focused on fundamental structure-property relationships. In this report, functional groups, such as terminal alkynes and pyridine groups, are installed on the tether between 1,4-benzene dicarboxylic acid (Hbdc) groups of the dimer ligands.
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December 2024
Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China Hefei Anhui 230026 China
The packing of organic molecular crystals is often dominated by weak non-covalent interactions, making their rearrangement under external stimuli challenging to understand. We investigate a pressure-induced single-crystal-to-single-crystal (SCSC) transformation between two polymorphs of 2,4,5-triiodo-1-imidazole using machine learning potentials. This process involves the rearrangement of halogen and hydrogen bonds combined with proton transfer within a complex solid-state system.
View Article and Find Full Text PDFACS EST Air
September 2024
Office of the Director, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505, United States.
During use of sodium hypochlorite bleach, gas-phase hypochlorous acid (HOCl) and chlorine (Cl) are released, which can react with organic compounds present in indoor air. Reactivity between HOCl/Cl and limonene, a common constituent of indoor air, has been observed. The purpose of this study was to characterize the chemical species generated from gas-phase reactions between HOCl/Cl and limonene.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Department of Chemical Engineering, Birla Institute of Technology and Science, Pilani, Rajasthan 333031, India.
Naphthalenediimide (NDI)-based donor-acceptor co-polymers with tunable electronic, optical, mechanical, and transport properties have shown immense potential as n-type conducting polymers in organic (opto)electronics. During the operation, the polymers undergo reduction at different charged states, which alters their (opto)electronic properties mainly due to the formation of the quasiparticles, polaron/bipolaron. The theoretical study based on quantum mechanical calculations can provide us with a detailed understanding of their (opto)electronic properties, which is missing to a great extent.
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