In this paper,the poly(acrylamide)hydrogel used to immobilize saccharomyces cerevisiae for asymmetric synthesis of R(-)-mandelic acid was prepared with free radical ploymerization in deionized water at room temperatur...In this paper,the poly(acrylamide)hydrogel used to immobilize saccharomyces cerevisiae for asymmetric synthesis of R(-)-mandelic acid was prepared with free radical ploymerization in deionized water at room temperature under nitrogen atmosphere.The influence of the composition of hydrogel,loading amount of cells and culture conditions on the asymmetric synthesis was investigated.Results show that PAAm hydrogel is a feasible carrier for immobilization of cells which is a potential alternative method to prepare enantiomerically pure R(-)-mandelic acid.展开更多
In this work, the optimization of hydrogen production by photo-fermentation bacteria immobilized on agar gel granule was systematic investigated in batch culture. Experiment focus on the effect of some important affec...In this work, the optimization of hydrogen production by photo-fermentation bacteria immobilized on agar gel granule was systematic investigated in batch culture. Experiment focus on the effect of some important affecting factors on photo-hydrogen production. Results indicated that immobilized Rhodopseudomonas faecalis RLD-53 exhibited the highest hydrogen yield of 3.15 mol H2/mol acetate under follow optimal condition: agar granule diameter of 2.5 mm, inoculum age of 24 h, agar concentration of 2%, biomass of 4 mg/ml in agar and light intensity of 9000 lux. More importantly, immobilized photo-fermentation bacteria not only can enhance hydrogen production but can increase acids-tolerance capacity, even at pH 5.0 hydrogen also was produced, and thus hopefully immobilized photo-fermentation bacteria can be applied in the combination of dark and photo-fermentation for hydrogen production with high yield.展开更多
Asymmetric synthesis of (-)-1-trimethylsilyl-ethanol with immobilized Saccharomyces cerevisiae cells in water/organic solvent biphasic system was studied. The effects of shake speed, hydrophobicity of organic solvent,...Asymmetric synthesis of (-)-1-trimethylsilyl-ethanol with immobilized Saccharomyces cerevisiae cells in water/organic solvent biphasic system was studied. The effects of shake speed, hydrophobicity of organic solvent, volume ratio of water phase to organic phase, pH value of aqueous phase and reaction temperature on the initial reaction rate, maximum yield and enantiomeric excess (ee) of the product were systematically explored. All the above-mentioned factors had significant influence on the reaction. n-Hexane was found to be the best organic solvent for the reaction. The optimum shake speed, volume ratio of water phase to organic phase, pH value and reaction temperature were 150 r.min-1, 1/2, 8 and 30 ℃ respectively, under which the maximum yield and enantiomeric excess of the product were as high as 96.8% and 95.7%, which are 15% and 16% higher than those of the corresponding reaction performed in aqueous phase. To our best knowledge, this is the most satisfactory result obtained.展开更多
Tumor necrosis factor α （TNF-α） and interferon-γ （IFN-γ） are cytokines with strong antitumor activities. They were reacted with a photoactive arylazide-4-azidobenzoic acid, resulting in photoactive TNF-α and ...Tumor necrosis factor α （TNF-α） and interferon-γ （IFN-γ） are cytokines with strong antitumor activities. They were reacted with a photoactive arylazide-4-azidobenzoic acid, resulting in photoactive TNF-α and IFN-γ. The infrared （IR） spectra of these products showed the characteristic absorption of an azido group at 2127 cm^-1. By photo-immobilization, this modified TNF-α and IFN-γ were immobilized on polystyrene membranes for cell culture to prepare biomaterials. The micro-morphology of photoactive cytokines was observed with a scanning electron microscope （SEM）. The inhibitory effect on growth of Hela cells and inducing apoptosis activity of these two cytokines were analyzed by growth curve, transmission electron microscope （TEM） and fluorescence active cell sorter （FACS）. The results showed that co-immobilization of IFN-γ and TNF-α had significant inhibitory effect on growth of Hela cells, inhibitory rate up to 82%, and IFN-γ had obviously synergistic action.展开更多
We isolated a novel laminarinase ULam111 from Flavobacterium sp. strain UMI-01. Purified ULam111 showed degradation activity against laminarin with the specific activity of 224 ± 18 U/mg at 30°C and pH 6.0. ...We isolated a novel laminarinase ULam111 from Flavobacterium sp. strain UMI-01. Purified ULam111 showed degradation activity against laminarin with the specific activity of 224 ± 18 U/mg at 30°C and pH 6.0. Its optimum temperature was 50°C, and degradation activities against laminarin were observed at 4°C - 80°C. With a laminarin degradation system, we investigated the preparation and properties of immobilized ULam111 with the use of the 11 types of carriers. The high activity recoveries of immobilized ULam111 were as follows: 19.4% for IB-S60P carrier beads (the non-ionic type), 15.6% for IB-S60S carrier beads (the non-ionic type), 11.9% for IB-150P carrier beads (the covalent type), and 7.1% for IB-C435 carrier beads (the cationic type). With the repeated use of immobilized ULam111, the enzyme activities immobilized on IB-S60S and those on IB-S60P remained at 40% and 30% respectively after the sixth trial. We selected IB-S60S as suitable beads for enzyme immobilization, and we attempted to construct a reactor system with ULam111 immobilized on IB-S60S beads. In this system, 1.2 - 1.9 g/L glucose was repeatedly produced from 30 mg/mL laminarin solutions after 20 hr when the reactor operation was repeated 10 times. We examined ethanol fermentation from the saccharified solutions with a marine-derived yeast (Saccharomyces cerevisiae C-19), and 0.51 - 0.58 g/L bioethanol was produced from the saccharified solution that contained 1.71 - 1.86 g/L of glucose.展开更多
Long-term societal prosperity depends on addressing the world’s energy and environmental problems,and photocatalysis has emerged as a viable remedy.Improving the efficiency of photocatalytic processes is fundamentall...Long-term societal prosperity depends on addressing the world’s energy and environmental problems,and photocatalysis has emerged as a viable remedy.Improving the efficiency of photocatalytic processes is fundamentally achieved by optimizing the effective utilization of solar energy and enhancing the efficient separation of photogenerated charges.It has been demonstrated that the fabrication ofⅢ–Ⅴsemiconductor-based photocatalysts is effective in increasing solar light absorption,long-term stability,large-scale production and promoting charge transfer.This focused review explores on the current developments inⅢ–Ⅴsemiconductor materials for solar-powered photocatalytic systems.The review explores on various subjects,including the advancement ofⅢ–Ⅴsemiconductors,photocatalytic mechanisms,and their uses in H2 conversion,CO_(2)reduction,environmental remediation,and photocatalytic oxidation and reduction reactions.In order to design heterostructures,the review delves into basic concepts including solar light absorption and effective charge separation.It also highlights significant advancements in green energy systems for water splitting,emphasizing the significance of establishing eco-friendly systems for CO_(2)reduction and hydrogen production.The main purpose is to produce hydrogen through sustainable and ecologically friendly energy conversion.The review intends to foster the development of greener and more sustainable energy source by encouraging researchers and developers to focus on practical applications and advancements in solar-powered photocatalysis.展开更多
A novel way for photo-immobilization with interferon- α（IFN- α） on the surface of polyurethane （PU） material, which makes PU condom more effective function in the future, was investigated. A kind of photoactive ...A novel way for photo-immobilization with interferon- α（IFN- α） on the surface of polyurethane （PU） material, which makes PU condom more effective function in the future, was investigated. A kind of photoactive arylazide-4-azidobenzoic acid was modified to IFN- α with the confirmation of IR and Raman spectrum. Micro morphology of the photo-immobilized cell factors was observed by FESEM as well as CSLM at the level of nanometer. Finally, the product with elementary test of anti-microbial was also evaluated.展开更多
A single-Rh-site catalyst(Rh-TPISP)that was ionically-embedded on a P(V)quaternary phosphonium porous polymer was evaluated for heterogeneous ethanol carbonylation.The[Rh(CO)I_(3)]^(2-)unit was proposed to be the acti...A single-Rh-site catalyst(Rh-TPISP)that was ionically-embedded on a P(V)quaternary phosphonium porous polymer was evaluated for heterogeneous ethanol carbonylation.The[Rh(CO)I_(3)]^(2-)unit was proposed to be the active center of Rh-TPISP for the carbonylation reaction based on detailed Rh L3-edge X-ray absorption near edge structure(XANES),X-ray photoelectron spectroscopy(XPS),and Rh extended X-ray absorption fine structure(EXAFS)analyses.As the highlight of this study,Rh-TPISP displayed distinctly higher activity for heterogeneous ethanol carbonylation than the reported catalytic systems in which[Rh(CO)_(2)I_(2)]^(-)is the traditional active center.A TOF of 350 h^(-1)was obtained for the reaction over[Rh(CO)I_(3)]^(2-),with>95%propionyl selectivity at 3.5 MPa and 468 K.No deactivation was detected during a near 1000 h running test.The more electron-rich Rh center was thought to be crucial for explaining the superior activity and selectivity of Rh-TPISP,and the formation of two ionic bonds between[Rh(CO)I_(3)]^(2-)and the cationic P(V)framework([P]^(+))of the polymer was suggested to play a key role in firmly immobilizing the active species to prevent Rh leaching.展开更多
文摘In this paper,the poly(acrylamide)hydrogel used to immobilize saccharomyces cerevisiae for asymmetric synthesis of R(-)-mandelic acid was prepared with free radical ploymerization in deionized water at room temperature under nitrogen atmosphere.The influence of the composition of hydrogel,loading amount of cells and culture conditions on the asymmetric synthesis was investigated.Results show that PAAm hydrogel is a feasible carrier for immobilization of cells which is a potential alternative method to prepare enantiomerically pure R(-)-mandelic acid.
文摘In this work, the optimization of hydrogen production by photo-fermentation bacteria immobilized on agar gel granule was systematic investigated in batch culture. Experiment focus on the effect of some important affecting factors on photo-hydrogen production. Results indicated that immobilized Rhodopseudomonas faecalis RLD-53 exhibited the highest hydrogen yield of 3.15 mol H2/mol acetate under follow optimal condition: agar granule diameter of 2.5 mm, inoculum age of 24 h, agar concentration of 2%, biomass of 4 mg/ml in agar and light intensity of 9000 lux. More importantly, immobilized photo-fermentation bacteria not only can enhance hydrogen production but can increase acids-tolerance capacity, even at pH 5.0 hydrogen also was produced, and thus hopefully immobilized photo-fermentation bacteria can be applied in the combination of dark and photo-fermentation for hydrogen production with high yield.
基金Supported by the National Natural Science Foundation of China(No.20076019)the Natural Science Foundation of Guang-dong Province(No.000444).
文摘Asymmetric synthesis of (-)-1-trimethylsilyl-ethanol with immobilized Saccharomyces cerevisiae cells in water/organic solvent biphasic system was studied. The effects of shake speed, hydrophobicity of organic solvent, volume ratio of water phase to organic phase, pH value of aqueous phase and reaction temperature on the initial reaction rate, maximum yield and enantiomeric excess (ee) of the product were systematically explored. All the above-mentioned factors had significant influence on the reaction. n-Hexane was found to be the best organic solvent for the reaction. The optimum shake speed, volume ratio of water phase to organic phase, pH value and reaction temperature were 150 r.min-1, 1/2, 8 and 30 ℃ respectively, under which the maximum yield and enantiomeric excess of the product were as high as 96.8% and 95.7%, which are 15% and 16% higher than those of the corresponding reaction performed in aqueous phase. To our best knowledge, this is the most satisfactory result obtained.
基金This work was supported by the China Postdoctoral Science Foundation under grant No.2004035588.
文摘Tumor necrosis factor α （TNF-α） and interferon-γ （IFN-γ） are cytokines with strong antitumor activities. They were reacted with a photoactive arylazide-4-azidobenzoic acid, resulting in photoactive TNF-α and IFN-γ. The infrared （IR） spectra of these products showed the characteristic absorption of an azido group at 2127 cm^-1. By photo-immobilization, this modified TNF-α and IFN-γ were immobilized on polystyrene membranes for cell culture to prepare biomaterials. The micro-morphology of photoactive cytokines was observed with a scanning electron microscope （SEM）. The inhibitory effect on growth of Hela cells and inducing apoptosis activity of these two cytokines were analyzed by growth curve, transmission electron microscope （TEM） and fluorescence active cell sorter （FACS）. The results showed that co-immobilization of IFN-γ and TNF-α had significant inhibitory effect on growth of Hela cells, inhibitory rate up to 82%, and IFN-γ had obviously synergistic action.
文摘We isolated a novel laminarinase ULam111 from Flavobacterium sp. strain UMI-01. Purified ULam111 showed degradation activity against laminarin with the specific activity of 224 ± 18 U/mg at 30°C and pH 6.0. Its optimum temperature was 50°C, and degradation activities against laminarin were observed at 4°C - 80°C. With a laminarin degradation system, we investigated the preparation and properties of immobilized ULam111 with the use of the 11 types of carriers. The high activity recoveries of immobilized ULam111 were as follows: 19.4% for IB-S60P carrier beads (the non-ionic type), 15.6% for IB-S60S carrier beads (the non-ionic type), 11.9% for IB-150P carrier beads (the covalent type), and 7.1% for IB-C435 carrier beads (the cationic type). With the repeated use of immobilized ULam111, the enzyme activities immobilized on IB-S60S and those on IB-S60P remained at 40% and 30% respectively after the sixth trial. We selected IB-S60S as suitable beads for enzyme immobilization, and we attempted to construct a reactor system with ULam111 immobilized on IB-S60S beads. In this system, 1.2 - 1.9 g/L glucose was repeatedly produced from 30 mg/mL laminarin solutions after 20 hr when the reactor operation was repeated 10 times. We examined ethanol fermentation from the saccharified solutions with a marine-derived yeast (Saccharomyces cerevisiae C-19), and 0.51 - 0.58 g/L bioethanol was produced from the saccharified solution that contained 1.71 - 1.86 g/L of glucose.
基金supported by the Nano&Material Technology Development Program through the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT(No.2022M3H4A1A04096380)and(No.2022M3H4A3A01082883)。
文摘Long-term societal prosperity depends on addressing the world’s energy and environmental problems,and photocatalysis has emerged as a viable remedy.Improving the efficiency of photocatalytic processes is fundamentally achieved by optimizing the effective utilization of solar energy and enhancing the efficient separation of photogenerated charges.It has been demonstrated that the fabrication ofⅢ–Ⅴsemiconductor-based photocatalysts is effective in increasing solar light absorption,long-term stability,large-scale production and promoting charge transfer.This focused review explores on the current developments inⅢ–Ⅴsemiconductor materials for solar-powered photocatalytic systems.The review explores on various subjects,including the advancement ofⅢ–Ⅴsemiconductors,photocatalytic mechanisms,and their uses in H2 conversion,CO_(2)reduction,environmental remediation,and photocatalytic oxidation and reduction reactions.In order to design heterostructures,the review delves into basic concepts including solar light absorption and effective charge separation.It also highlights significant advancements in green energy systems for water splitting,emphasizing the significance of establishing eco-friendly systems for CO_(2)reduction and hydrogen production.The main purpose is to produce hydrogen through sustainable and ecologically friendly energy conversion.The review intends to foster the development of greener and more sustainable energy source by encouraging researchers and developers to focus on practical applications and advancements in solar-powered photocatalysis.
基金Funded by the Guangdong Technology Projects (No.2006B35802003)the Natural Science Foundation of Guangdong Province (No.8451063101000345)the Opening Project of MOE Key laboratory of Laser Life Science, South China Normal University, Guangzhou 510631, China
文摘A novel way for photo-immobilization with interferon- α（IFN- α） on the surface of polyurethane （PU） material, which makes PU condom more effective function in the future, was investigated. A kind of photoactive arylazide-4-azidobenzoic acid was modified to IFN- α with the confirmation of IR and Raman spectrum. Micro morphology of the photo-immobilized cell factors was observed by FESEM as well as CSLM at the level of nanometer. Finally, the product with elementary test of anti-microbial was also evaluated.
文摘A single-Rh-site catalyst(Rh-TPISP)that was ionically-embedded on a P(V)quaternary phosphonium porous polymer was evaluated for heterogeneous ethanol carbonylation.The[Rh(CO)I_(3)]^(2-)unit was proposed to be the active center of Rh-TPISP for the carbonylation reaction based on detailed Rh L3-edge X-ray absorption near edge structure(XANES),X-ray photoelectron spectroscopy(XPS),and Rh extended X-ray absorption fine structure(EXAFS)analyses.As the highlight of this study,Rh-TPISP displayed distinctly higher activity for heterogeneous ethanol carbonylation than the reported catalytic systems in which[Rh(CO)_(2)I_(2)]^(-)is the traditional active center.A TOF of 350 h^(-1)was obtained for the reaction over[Rh(CO)I_(3)]^(2-),with>95%propionyl selectivity at 3.5 MPa and 468 K.No deactivation was detected during a near 1000 h running test.The more electron-rich Rh center was thought to be crucial for explaining the superior activity and selectivity of Rh-TPISP,and the formation of two ionic bonds between[Rh(CO)I_(3)]^(2-)and the cationic P(V)framework([P]^(+))of the polymer was suggested to play a key role in firmly immobilizing the active species to prevent Rh leaching.
