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Cheng Zhou,Shubao Shen,Xiumin Wu,Bo Jiang 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.12
Immobilized trypsin in mesoporous silica foams was used to catalyze dipeptide synthesis in hydrophilic organic solvent instead of soluble form. The area surface of nano support was measured. The catalytic activity, coupled yield and kinetic characterization of immobilized trypsin were examined. Bz-Arg-OEt was chosen as the acyl donor with Lys-OH as the nucleophile. The trypsin-catalyzed synthesis condition was optimized, such as catalytic temperature,pH, reaction time, physical properties and content of organic solvents, together with the added enzyme amount. The immobilized trypsin showed 112.8% of residual activity with 91.9% of coupled yield, and the kinetic parameters exhibited accessibility for transmission. The product yield of 5.8% was reached at the optimum conditions for enzymatic synthesis of dipeptide: 800 mg of wet immobilized trypsin (200 mg/g support) was used in Tris-HCl buffer (0.1 mol/L, pH 8.0) containing 80% (v/v) ethanol solvents for 6 h of reaction time at 35 oC. This attempt of immobilized strategy for trypsin in nanopores renders the possibility of wide application of inorganic nano-sized support in catalytic synthesis process, which can avoid usage of large amounts of organic solvents in washing steps by chemical methods and reduce the tedious purification process of its soluble form.
Cheng Zhou,Shubao Shen,Bo Jiang,Zecui Sheng,Shemin Zhu 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.3
Chemically modified macromolecules were assembled with adsorptive trypsin in mesoporous silica foams (MCFs) to establish covalent linkage. Effects of catalytic properties and stability of immobilized trypsin were examined. The addition of chemically modified protein (BSA) and polysaccharide (ficoll) to the immobilized trypsin exhibited high coupled yield (above 90%) and relative activities (174.5% and 175.9%, respectively), showing no protein leaching after incubating for 10 h in buffers. They showed broader pH and temperature profiles, while the half life of thermal stability of BSA-modified preparation at 50 ℃ increased to 1.3 and 2.3 times of unmodified and free trypsin,respectively. The modified trypsin in aqueous-organic solvents exhibited 100% activity after 6 h at 50 ℃. The kinetic parameters of trypsin preparations and suitable pore diameter of MCFs warranted compatibility of covalent modification for substrate transmission. The covalent crowding modification for immobilized trypsin in nanopores establishes suitable and accessible microenvironment and renders possibility of biological application.
Bo Yang,Yuesong Shen,Yun Su,Peiwen Li,Yan-Wei Zeng,Shubao Shen,Shemin Zhu 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.50 No.-
A novel Mn-Ce-Nb-Ox/P84 catalyticfilter for synergetic removal of particulates and NO was designed andprepared by a new method using functional foaming coating. Removal characteristics of nitrogen oxides(including catalyst loading amount, O2 concentration, NH3/NO molar ratio, H2O and SO2) andparticulates, were systematically studied. Results showed that the NO removal efficiency of catalyticfilter reached 95.3% at 200 C, as the catalyst loading amount,filtration velocity and mole ratio of NH3/NOwere set to be 450 g/m2, 1 m/min and 1, respectively. The removal characteristic of particulates of Mn-Ce-Nb-Ox/P84 catalyticfilter belonged surfacefiltration and the PM2.5 removal efficiency reached 99.98%.
Zhiwei Xue,Shemin Zhu,Yuesong Shen,Shubao Shen,Chengliang Li 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.30 No.-
Promotional effects of Ce4+, La3+ and Nd3+ incorporations on FeCu2O3.5/ATS for decomposing N2O wereinvestigated. Results showed that all the ions especially La3+ can dramatically improve the catalyticperformance. FeCu2La1.5Ox/ATS, the optimal catalyst, can decompose 100% N2O at 550 8C. The formedperovskite-type LaFeO3 and spinel-type CuLa2O4 largely improved catalytic performance. The ionmodification increased N2O adsorption capacity, and La3+-doped catalyst enhanced desorption ability ofsurface oxygen. Both effects can accelerate the rate-determine steps of N2O decomposition reaction,promote catalytic performance. Moreover, the supported catalysts studied were economic efficiency forapplication.
She-Min Zhu,Da-Hai Zheng,Yuesong Shen,Yun-Shun Qiu,Bing Li,Yan-Wei Zeng,Shubao Shen,Shemin Zhu 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.24 No.-
Effects of catalyst loading amount, reaction temperature, O2 concentration, NH3/NO molar ratio and SO2 on low-temperature catalytic performance of the Mn–La–Ce–Ni–Ox (Mn/La/Ce/Ni = 2.5:2.5:1:1 in mol)/ PPS for NH3-SCR of NO were mainly studied. Results showed that the filter with catalyst loading amount of 250 g/m2 obtained more than 95% NO removal efficiency at 200 8C under filtration velocity of 1 m/min. The NO removal efficiency was still above 85% by injecting 300 ppm SO2 at 200 8C. Anyway, the Mn–La– Ce–Ni–Ox/PPS catalytic filter is promising to achieve the expectation of simultaneous removing particulate and NOx from low-sulfur flue gas in cement kiln.
Cheng Zhou,Shemin Zhu,Xiuming Wu,Bo Jiang,Tao Cen,Shubao Shen 한국생물공학회 2010 Biotechnology and Bioprocess Engineering Vol.15 No.3
Penicillin acylase (PA) is known to regulate the microenvironment of nanospores. In this study, nanopores containing chemically-modified macromolecules co-assembled with immobilized PA were constructed. We also investigated the various types of functionalized mesocellular siliceous foams (MCFs) commonly used for the immobilization of PA by measuring the catalytic performance and stability of each PA preparation. Amino-MCF activated by p-benzoquinone was chosen as the optimum support for PA immobilization. Successful modification of macromolecules was verified by FT-IR and ultraviolet (UV)spectroscopy. The specific activity of PA co-assembled with dextran 10 k was 99.1 U/mg, which was 1.5-fold that of pristine immobilized PA, while the optimum pH was shifted to neutral. Compared to pristine immobilized and free PA, the optimum temperatures for the modified PA were 5 and 10oC higher, respectively. The residual activity of the ficoll derivative of PA after treatment at 50oC for 6 h was 70%, and this was later increased to 214.5% compared to that of pristine immobilized PA. The dextran 10 k derivative of PA exhibited 90.2% residual activity after 25times of continuous use. The results show that chemicallymodified macromolecules co-assembled with PA in amino-MCF provided a suitable microenvironment for enzyme stability.
Cheng Zhou,Anming Wang,Zhiqiang Du,Shemin Zhu,Shubao Shen 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.4
Macromolecular reagents were co-assembled with penicillin acylase (PA) and immobilized in mesocellular siliceous foams (MCFs) to resemble living cells. Types and concentrations of macromolecules were studied. The catalytic characteristic and stability of PA preparations were also investigated. PA assembled with dextran 10 k in MCFs showed maximum specific activity, 1.32-fold of that of the solely immobilized PA. The optimum pH of dextran and BSA derivatives shifted to neutrality, and the optimum temperature increased by 10 oC. Also, Km of BSA derivative of PA declined 56.7% compared to solely immobilized PA, while the Kcat/Km of PA assembled with BSA was enhanced to 147%. After incubation at 50℃ for 6 h, residual activity of PA assembled with BSA exhibited 53.0%. The ficoll derivative showed 82.8% of its initial activity at 4 oC after 8-week storage. The results indicated that macromolecular reagents assembled with PA in MCFs could dramatically improve the catalytic performance and stability of im- mobilized enzyme.