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Extending the previous work [1], we establish well-posedness results for a more general class of semilinear wave equations with exponential growth. First, we investigate the well-posedness in the energy space. Then, we prove the propagation of the regularity in the Sobolev spaces HS(IR^2) with s 〉 1. Finally, an ill-posedness result is obtained in HS(IR^2) for s 〈 1. 相似文献
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Dr. Romain Plais Guy Gouarin Amélie Bournier Olfa Zayene Vanessa Mussard Flavien Bourdreux Dr. Jérome Marrot Arnaud Brosseau Dr. Anne Gaucher Dr. Gilles Clavier Dr. Jean-Yves Salpin Prof. Dr. Damien Prim 《Chemphyschem》2023,24(2):e202200524
Modulation and fine-tuning of the strength of weak interactions to bind anions are described in a series of synthetic receptors. The general design of the receptors includes both a urea motif and a tetrazine motif. The synthetic sequence towards three receptors is detailed. Impacts of H-bond strength and linker length between urea and tetrazine on chloride complexation are studied. Binding properties of the chloride anion are examined in both the ground and excited states using a panel of analytical methods (NMR spectroscopy, mass spectrometry, UV/Visible spectroscopies, and fluorescence). A ranking of the receptors by complexation strength has been determined, allowing a better understanding of the structure-properties relationship on these compounds. 相似文献
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Ali Nel-H Hmidet N Ghorbel-Bellaaj O Fakhfakh-Zouari N Bougatef A Nasri M 《Applied biochemistry and biotechnology》2011,164(7):1096-1110
Alkaline proteases from the viscera of the striped seabream (Lithognathus mormyrus) were extracted and characterized. Interestingly, the crude enzyme was active over a wide range of pH from 6.0 to 11.0, with
an optimum pH at the range of 8.0–10.0. In addition, the crude protease was stable over a broad pH range (5.0–12.0). The optimum
temperature for enzyme activity was 50 °C. The crude alkaline proteases showed stability towards various surfactants and bleach
agents and compatibility with some commercial detergents. It was stable towards several organic solvents and retained more
than 50% of its original activity after 30 days of incubation at 30 °C in the presence of 25% (v/v) dimethyl sulfoxide, N,N-dimethylformamide, diethyl ether, and hexane. The crude enzyme extract was also tested for shrimp waste deproteinization
in the preparation of chitin. The protein removal with a ratio enzyme/substrate of 10 was about 79%. 相似文献
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Ghorbel-Bellaaj O Jellouli K Younes I Manni L Ouled Salem M Nasri M 《Applied biochemistry and biotechnology》2011,164(4):410-425
A solvent-stable protease-producing bacterium was isolated and identified as Pseudomonas aeruginosa A2. The strain was found to produce high level of protease activity when grown in media containing only fresh shrimp waste
(FSW) or shrimp waste powder (SWP), indicating that it can obtain its carbon, nitrogen, and salts requirements directly from
shrimp waste. Maximum protease activities 17,000 and 12,000 U/mL were obtained with 80 g/L SWP and 135 g/L FSW, respectively.
The optimum temperature and pH for protease activity were 60 °C and 8.0, respectively. The crude protease, at different enzyme/substrate
(E/S) ratio, was tested for the deproteinization of shrimp waste to produce chitin. The crude enzyme of P. aeruginosa A2 was found to be effective in the deproteinization of shrimp waste. The protein removals after 3 h hydrolysis at 40 °C
with an E/S ratio of 0.5 and 5 U/mg protein were about 56% and 85%, respectively. 13C CP/MAS-NMR spectral analysis of the chitin prepared by treatment with the crude protease was carried out and was found to
be similar to that of the commercial α-chitin. These results suggest that enzymatic deproteinization of shrimp waste by A2
protease could be applicable to the chitin production process. 相似文献
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Tabbene O Karkouch I Slimene IB Elfeddy N Cosette P Mangoni ML Jouenne T Limam F 《Applied biochemistry and biotechnology》2011,164(1):34-44
When cultured in minimal growth medium, the B38 strain of Bacillus subtilis did not exhibit any antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) clinical isolate. Coculturing B38 strain with viable MRSA cells weakly increased antibacterial activity production
(20 AU/ml). Addition of dead MRSA cells in a B38 culture, increased by 8-fold the B. subtilis strain antibacterial activity reaching 160 AU/ml against MRSA strain. This antibacterial activity recovered from cell-free
supernatants was stimulated by an autoinducing compound which is sensitive to the action of proteinase K suggesting a proteinaceous
nature. This compound was heat-stable till 80 °C and showed a molecular mass around 20 kDa as determined by SDS-PAGE. These
results suggest that the production of antibacterial compounds by B38 strain is dependent on the amount of the autoinducing
compound. 相似文献
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Laila Manni Kemel Jellouli Olfa Ghorbel-Bellaaj Rym Agrebi Anissa Haddar Alya Sellami-Kamoun Moncef Nasri 《Applied biochemistry and biotechnology》2010,160(8):2308-2321
The current increase in amount of shrimp wastes produced by the shrimp industry has led to the need in finding new methods
for shrimp wastes disposal. In this study, an extracellular organic solvent- and oxidant-stable metalloprotease was produced
by Bacillus cereus SV1. Maximum protease activity (5,900 U/mL) was obtained when the strain was grown in medium containing 40 g/L shrimp wastes
powder as a sole carbon source. The optimum pH, optimum temperature, pH stability, and thermal stability of the crude enzyme
preparation were pH 8.0, 60 °C, pH 6–9.5, and <55 °C, respectively. The crude protease was extremely stable toward several
organic solvents. No loss of activity was observed even after 60 days of incubation at 30 °C in the presence of 50% (v/v) dimethyl sulfoxide and ethyl ether; the enzyme retained more than 70% of its original activity in the presence of ethanol
and N,N-dimethylformamide. The protease showed high stability toward anionic (SDS) and non-ionic (Tween 80, Tween 20, and Triton
X-100) surfactants. Interestingly, the activity of the enzyme was significantly enhanced by oxidizing agents. In addition,
the enzyme showed excellent compatibility with some commercial liquid detergents. The protease of B. cereus SV1, produced under the optimal culture conditions, was tested for shrimp waste deproteinization in the preparation of chitin.
The protein removal with a ratio E/S of 20 was about 88%. The novelties of the SV1 protease include its high stability to organic solvents and surfactants. These
unique properties make it an ideal choice for application in detergent formulations and enzymatic peptide synthesis. In addition,
the enzyme may find potential applications in the deproteinization of shrimp wastes to produce chitin. 相似文献
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Soussi Siwar Essid Rym Hardouin Julie Gharbi Dorra Elkahoui Salem Tabbene Olfa Cosette Pascal Jouenne Thierry Limam Ferid 《Applied biochemistry and biotechnology》2019,187(4):1460-1474
Applied Biochemistry and Biotechnology - An endophytic Bacillus amyloliquefaciens strain called C5, able to produce biosurfactant lipopeptides with a broad antibacterial activity spectrum, has been... 相似文献