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Jiao Y.-L.,Huaihai Institute of Technology | Jiao Y.-L.,Jiangsu Marine Resource Development Research Institute | Wang S.-J.,Huaihai Institute of Technology | Lv M.-S.,Huaihai Institute of Technology | And 4 more authors.
Journal of Industrial Microbiology and Biotechnology | Year: 2014

The dextranase added in current commercial dextranase-containing mouthwashes is largely from fungi. However, fungal dextranase has shown much higher optimum temperature than bacterial dextranase and relatively low activity when used in human oral cavities. Bacterial dextranase has been considered to be more effective and suitable for dental caries prevention. In this study, a dextranase (Dex410) from marine Arthrobacter sp. was purified and characterized. Dex410 is a 64-kDa endoglycosidase. The specific activity of Dex410 was 11.9 U/mg at optimum pH 5.5 and 45 C. The main end-product of Dex410 was isomaltotriose, isomaltoteraose, and isomaltopentaose by hydrolyzing dextran T2000. In vitro studies showed that Dex410 effectively inhibited the Streptococcus mutans biofilm growth in coverage, biomass, and water-soluble glucan (WSG) by more than 80, 90, and 95 %, respectively. The animal experiment revealed that for short-term use (1.5 months), both Dex410 and the commercial mouthwash Biotene (Laclede Professional Products, Gardena, CA, USA) had a significant inhibitory effect on caries (p = 0.0008 and 0.0001, respectively), while for long-term use (3 months), only Dex410 showed significant inhibitory effect on dental caries (p = 0.005). The dextranase Dex410 from a marine-derived Arthrobacter sp. strain possessed the enzyme properties suitable to human oral environment and applicable to oral hygiene products. © 2013 Society for Industrial Microbiology and Biotechnology.

Zhu C.-S.,China University of Mining and Technology | Zhu C.-S.,Jiangsu Marine Resource Development Research Institute | Wang L.-P.,China University of Mining and Technology | Chen Y.-R.,Suzhou University of Science and Technology
Zhongguo Kuangye Daxue Xuebao/Journal of China University of Mining and Technology | Year: 2012

Tin acid phosphate (SnP) was used as adsorbent for the removal of Cu(II) from aqueous solutions. The extent of adsorption was investigated as a function of pH, contact time, adsorbate concentration, reaction temperature with batch experiments. Adsorption mechanism was probed by thermodynamics analysis and potentiometric titration. The results show that the amount of adsorbed copper ions increases with the increase of solution pH in the examined range (3~6.5) and reaction time. The sorption process follows pseudo-second-order kinetics very well. The equilibrium data fits better to the Langmuir isotherm equation. The maximum sorption capacity amounts to 48.69 mg/g at 20°C. The free energy E s (kJ/mol) got from the D-R isotherm indicates the sorption process is a chemical ion-exchange mechanism. The ion-exchange reaction happens between Cu 2+ and H +, which is spontaneous and endothermic. Adsorption experiments conducted in stimulated seawater find satisfactory adsorption capacity, 21.87 mg/g, at the NaCl concentration of 0.6 mol/L, which amounts to 93.3% of the counterpart at fresh water media. So it is feasible for tin acid phosphate in removing Cu 2+ from hyper-saline media.

Liu L.,Jiangsu Marine Resource Development Research Institute | Liu L.,Huaihai Institute of Technology | Liu D.,Huaihai Institute of Technology | Xia Z.,Huaihai Institute of Technology | And 9 more authors.
Monatshefte fur Chemie | Year: 2013

We report a facile, efficient procedure for selective oxidation of activated alcohols by use of a novel supported ionic-liquid catalyst produced by coating polystyrene-TEMPO resin with the ionic liquid [bmim]PF6 and CuCl2. The oxidation affords aldehydes or ketones in excellent yield and with high selectivity. It is worthy of note that the supported ionic-liquid layer substantially enhances catalytic activity, and the catalyst can easily be recycled. © 2012 Springer-Verlag.

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