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Construction of a CaHPO4-PGUS1 hybrid nanoflower through protein-inorganic self-assembly, and its application

Tian Jiang, Yuhui Hou, Tengjiang Zhang, Xudong Feng, Chun Li

《化学科学与工程前沿（英文）》 2019年 第13卷 第3期   页码 554-562 doi: 10.1007/s11705-019-1834-z

摘要： Glycyrrhetinic acid 3- -mono- -D-glucuronide (GAMG), an important pharmaceutical intermediate and functional sweetener, has broad applications in the food and medical industries. A green and cost-effective method for its preparation is highly desired. Using site-directed mutagenesis, we previously obtained a variant of -glucuronidase from Li-3 (PGUS1), which can specifically transform glycyrrhizin (GL) into GAMG. In this study, a facile method was established to prepare a CaHPO -PGUS1 hybrid nanoflower for enzyme immobilization, based on protein-inorganic hybrid self-assembly. Under optimal conditions, 1.2 mg of a CaHPO -PGUS1 hybrid nanoflower precipitate with 71.2% immobilization efficiency, 35.60 mg∙g loading capacity, and 118% relative activity was obtained. Confocal laser scanning microscope and scanning electron microscope results showed that the enzyme was encapsulated in the CaHPO -PGUS1 hybrid nanoflower. Moreover, the thermostability of the CaHPO -PGUS1 hybrid nanoflower at 55°C was improved, and its half-life increased by 1.3 folds. Additionally, the CaHPO -PGUS1 hybrid nanoflower was used for the preparation of GAMG through GL hydrolysis, with the conversion rate of 92% in 8 h, and after eight consecutive runs, it had 60% of its original activity.

关键词： β-glucuronidase     enzyme-inorganic hybrid nanoflower     biotransformation     glycyrrhizin     glycyrrtinic acid 3-O-mono-β-D-glucuronide    

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Diffusion process in enzyme–metal hybrid catalysts

《化学科学与工程前沿（英文）》 2022年 第16卷 第6期   页码 921-929 doi: 10.1007/s11705-022-2144-4

摘要： Enzyme–metal hybrid catalysts bridge the gap between enzymatic and heterogeneous catalysis, which is significant for expanding biocatalysis to a broader scope. Previous studies have demonstrated that the enzyme–metal hybrid catalysts exhibited considerably higher catalytic efficiency in cascade reactions, compared with that of the combination of separated enzyme and metal catalysts. However, the precise mechanism of this phenomenon remains unclear. Here, we investigated the diffusion process in enzyme–metal hybrid catalysts using Pd/lipase-Pluronic conjugates and the combination of immobilized lipase (Novozyme 435) and Pd/C as models. With reference to experimental data in previous studies, the Weisz–Prater parameter and efficiency factor of internal diffusion were calculated to evaluate the internal diffusion limitations in these catalysts. Thereafter, a kinetic model was developed and fitted to describe the proximity effect in hybrid catalysts. Results indicated that the enhanced catalytic efficiency of hybrid catalysts may arise from the decreased internal diffusion limitation, size effect of Pd clusters and proximity of the enzyme and metal active sites, which provides a theoretical foundation for the rational design of enzyme–metal hybrid catalysts.

关键词： enzyme–metal hybrid catalyst     internal diffusion     proximity effect     kinetic model    

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Self-assembly of metal-cholesterol oxidase hybrid nanostructures and application in bioconversion of

Yu Xin, Qiuyue Gao, Yu Gu, Mengyao Hao, Guangming Fan, Liang Zhang

《化学科学与工程前沿（英文）》 2021年 第15卷 第3期   页码 615-629 doi: 10.1007/s11705-020-1989-7

摘要： A cholesterol oxidase (COD) was hybridized with Ca , Zn , Al , Fe and Mn . After precipitation with PO at 4 °C for 72 h, the resulting pellets were freeze-dried. In scanning electron microscopy assays, the metal-COD complexes revealed flower-like or granular structures after hybridization. Fourier transform infrared spectroscopy assay revealed the characteristic peaks of both the enzyme and metal materials. X-ray diffraction analysis indicated that COD was encapsulated in CaHPO ·2H O-, Zn (PO ) ·4H O-, AlPO -, FeP - and Mn (PO ) ·3H O-based nanostructures, respectively. Differential scanning calorimetry assay indicated significant increases in thermo-denaturation temperatures from 60.5 °C to 167.02 °C, 167.02 °C, 137.70 °C, 172.85 °C and 160.99 °C, respectively. Using steroid derivatives as substrates, this enzyme could convert cholesterol, pregnenolone, dehydroepiandrosterone, ergosterol, -sitosterol and stigmasterol to related single products. Hybridization in metal-based nanostructures could significantly enhance the initial conversion ratio and reaction stability of the enzyme. In addition, substrate selectivity could be affected by various metal materials. Briefly, using Ca , Zn , Al , Fe and Mn as hybrid raw materials could help to encapsulate COD in related metal-enzyme nanostructures, and could help to promote the stability and tolerant properties of the enzyme, while also enhancing its catalytic characteristics.

关键词： cholesterol oxidase     metal-enzyme hybridization     nanostructures     sterol derivatives     bioconversion    

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Designer enzyme for green materials innovation: Lactate-polymerizing enzyme as a key catalyst

Seiichi Taguchi

《化学科学与工程前沿（英文）》 2017年 第11卷 第1期   页码 139-142 doi: 10.1007/s11705-017-1636-0

摘要： Establishment of the regeneratable whole-cell catalyst platform for the?production of biobased polymeric materials is a?typical topic of synthetic biology. In this commentary, discovery story of a “lactate-polymerizing enzyme” (LPE)?and LPE-based?achievements for creating a new variety of polyesters with incorporated unnatural monomers are presented. Besides the importance of microbial platform itself is discussed referring to the “ballooning”- .

关键词： synthetic biology     enzyme evolutionary engineering     polyhydroxyalkanoate    

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Formation of secondary inorganic aerosol in a frigid urban atmosphere

《环境科学与工程前沿（英文）》 2022年 第16卷 第2期 doi: 10.1007/s11783-021-1452-0

摘要：

•Harbin showed relatively high threshold RH (80%) for apparent increase of SOR.

关键词： Haze     Sulfate     Nitrate     Heterogeneous chemistry     Biomass burning     Northeast China    

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Influence of glucose feeding on the ligninolytic enzyme production of the white-rot fungus Phanerochaete

ZHOU Xiaoyan, WEN Xianghua, FENG Yan

《环境科学与工程前沿（英文）》 2007年 第1卷 第1期   页码 89-94 doi: 10.1007/s11783-007-0017-1

摘要： The present work studied the influence of glucose feeding on the ligninolytic enzyme production of in a nitrogen-limited (C/N ratio is 56/8.8 mmol/L) medium. Several sets of shaking flask experiments were conducted. The results showed that 2 g/L glucose feeding on the first day of the culture (24 h after the inoculation) stimulated both fungal biomass growth and enzyme production. The manganese peroxidase (MnP) activity was 2.5 times greater than that produced in cultures without glucose feeding. Furthermore, the glucose feeding mode in fed-batch culture was also investigated. Compared to cultures with glucose feeding every 48 h, cultures with glucose feeding of 1.5 g/L (final concentration) every 24 h produced more enzymes. The peak and total yield of MnP activity were 2.7 and 3 times greater compared to the contrast culture, respectively, and the enzyme was kept stable for 4 days with an activity of over 200 U/L.

关键词： enzyme production     fed-batch culture     nitrogen-limited     inoculation     mmol/L    

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Detection of Escherichia coli in wastewater based on enzyme immunoassay

XI Haiyan, CAI Qiang, HE Miao, SHI Hanchang

《环境科学与工程前沿（英文）》 2007年 第1卷 第3期   页码 381-384 doi: 10.1007/s11783-007-0065-6

摘要： This research describes a fast detection method on the basis of enzyme-linked immunosorbent assay (ELISA) for in drainage of wastewater treatment plants. Optimized conditions such as the reaction format (sandwich or direct), the concentrations of diluted horse radish peroxidase (HRP)- conjugate, and anti-HPR antibody and pretreatment of were studied. Those results showed that the linear range of detection for was 10 cfu/mL– 6 × 10 cfu/mL. Compared with conventional methods, it is a convenient and sensitive detection method with low cost.

关键词： conventional     sandwich     pretreatment     enzyme-linked immunosorbent     detection    

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Enzyme@bismuth-ellagic acid: a versatile platform for enzyme immobilization with enhanced acid-base stability

《化学科学与工程前沿（英文）》 2023年 第17卷 第6期   页码 784-794 doi: 10.1007/s11705-022-2278-4

摘要： In situ encapsulation is an effective way to synthesize enzyme@metal–organic framework biocatalysts; however, it is limited by the conditions of metal–organic framework synthesis and its acid-base stability. Herein, a biocatalytic platform with improved acid-base stability was constructed via a one-pot method using bismuth-ellagic acid as the carrier. Bismuth-ellagic acid is a green phenol-based metal–organic framework whose organic precursor is extracted from natural plants. After encapsulation, the stability, especially the acid-base stability, of amyloglucosidases@bismuth-ellagic acid was enhanced, which remained stable over a wide pH range (2–12) and achieved multiple recycling. By selecting a suitable buffer, bismuth-ellagic acid can encapsulate different types of enzymes and enable interactions between the encapsulated enzymes and cofactors, as well as between multiple enzymes. The green precursor, simple and convenient preparation process provided a versatile strategy for enzymes encapsulation.

关键词： bismuth-ellagic acid     in situ encapsulation     enzyme@MOF biocomposites    

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Soil enzyme activities and their indication for fertility of urban forest soil

SHAN Qihua, YU Yuanchun, ZHANG Jinchi, YU Jian

《环境科学与工程前沿（英文）》 2008年 第2卷 第2期   页码 218-223 doi: 10.1007/s11783-008-0037-5

摘要： To reveal the biological characteristics of urban forest soil and the effects of soil enzyme on soil fertility as well as the correlation between physicochemical properties and enzyme activities, 44 urban forest soil profiles in Nanjing were investigated. Basic soil physicochemical properties and enzyme activities were analyzed in the laboratory. Hydrogen peroxidase, dehydrogenase, alkaline phosphatase, and cellulase were determined by potassium permanganate titration, TTC (CHN·Cl) colorimetry, phenyl phosphate dinatrium colorimetry, and anthrone colorimetry, respectively. The result showed that soil pH, organic carbon (C), and total nitrogen (N) had great effects on hydrogen peroxidase, dehydrogenase, and alkaline phosphatase activities in 0–20 cm thick soil. However, pH only had great effect on hydrogen peroxidase, dehydrogenase, and alkaline phosphatase activities in 20–40 cm thick soil. Hydrogen peroxidase, dehydrogenase, and alkaline phosphatase were important biological indicators for the fertility of urban forest soil. Both in 0–20 cm and 20–40 cm soil, soil enzyme system (hydrogen peroxidase, dehydrogenase, alkaline phosphatase, and cellulase) had a close relationship with a combination of physicochemical indicators (pH, organic C, total N, available K, available P, cation exchange capacity (CEC), and microbial biomass carbon (C)). The more soil enzyme activities there were, the higher the fertility of urban forest soil.
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Spectrokinetics study of probable effects of diverse inorganic ions on bleaching of dye

Rafia AZMAT, Masooda QADRI, Fahim UDDIN

《化学科学与工程前沿（英文）》 2011年 第5卷 第1期   页码 131-138 doi: 10.1007/s11705-010-0556-z

摘要： Toluidine blue (TB) is an important anticoagulant metachromasia molecule showing a pronounced variation in the visible spectrum due to the aggregation phenomenon and electrostatic interaction with the charged synthetic and biologic polymers. The current study describes the interactive role of diverse inorganic material ions on the bleaching of toluidine blue (tolonium chloride) (TB ) with urea in acidic and basic media using the spectrophotometric technique. The spectra of TB and urea with different cations and anions were monitored and their characteristic features are presented here. The negative effect of added cations on reduction may be the result of altered electron pathways which led to suppression of the reduction/bleaching of TB, while a slight decrease in dye reduction by added anions may be due to the scavenging of the OH* radical. It has been observed in the case of Co that in addition to the electron-transfer reaction, other processes like layer and precipitate formation also appear to be taking place. The dye bleaching process followed pseudo first order kinetics with respect to TB, urea, and H ion, whereas significant decoloration in the presence of urea proved that reductants control the redox reaction. No decoloration in acidic medium with diverse ions was seen compared to alkaline media, showing that water pH played an important role in the bleaching of dye. The reduction/bleaching of dye was investigated at different temperatures, and energy parameters were evaluated for a TB -Urea reaction, including the energy of activation ( = 39.60 kJ·mol ), enthalpy of activation (? = 34?kJ·mol ), entropy of activation (? = 146.5 kJ mol ·K ), and free energy of activation (ΔG* = -52.35 kJ·mol ). A mechanism of interaction of diverse ions in dye bleaching and a mechanism of reduction based on the above findings is proposed.

关键词： TB     diverse ions     suppress     decoloration    

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Organic and inorganic phosphorus uptake by bacteria in a plug-flow microcosm

Jinbo ZHAO, Xuehua LIU

《环境科学与工程前沿（英文）》 2013年 第7卷 第2期   页码 173-184 doi: 10.1007/s11783-013-0494-3

摘要： Phosphorus (P) is a vital nutrient for sustaining natural water productivity. Both particulate and dissolved forms of organic and inorganic P are potentially important sources of bioavailable P for primary and secondary producers. A microcosm system to imitate the bacterial community in Plym river sediment and pore water is described and bacterial uptake rates for inorganic and organic phosphorus are presented in this paper. The aim of this study was to investigate the uptake of two organic phosphorus compounds (phytic acid and D-glucose-6-phosphate) by freshwater bacteria. The bioreactors comprise glass columns packed with two types of small glass beads on which bacterial biofilm can develop. The glass beads with different porosity were introduced to simulate River SPM. The selected P compounds spiked into the inflow of the microcosm, and measured the step change of P concentration in the outflow to investigate the behavior of bacterial uptake of nutrients. The results showed that organic phosphorus was converted into inorganic phosphorus but the conversion rate depended on the type of phosphorus species. One experiment suggested that phytic acid (refractory) could displace phosphate from the biofilm surface; the other experiment showed that D-glucose-6-phosphate (labile) could be hydrolysed and utilized easily by the bacteria. The results also suggested that bacteria might break down the C-P bonds to utilize the carbon. Further experiments should investigate the effect of varying the C:N:P ratio in the microcosm system to determine which nutrient limits bacteria uptake.

关键词： organic phosphorus     bacteria     uptake    

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Immobilization of laccase on organic–inorganic nanocomposites and its application in the removal of phenolic

《化学科学与工程前沿（英文）》 2023年 第17卷 第7期   页码 867-879 doi: 10.1007/s11705-022-2277-5

摘要： Polydopamine-functionalized nanosilica was synthesized using an inexpensive and easily obtainable raw material, mild reaction conditions, and simple operation. Subsequently, a flexible spacer arm was introduced by using dialdehyde starch as a cross-linking agent to bind with laccase. A high loading amount (77.8 mg∙g‒1) and activity retention (75.5%) could be achieved under the optimum immobilization conditions. Thermodynamic parameters showed that the immobilized laccase had a lower thermal deactivation rate constant and longer half-life. The enhancement of thermodynamic parameters indicated that the immobilized laccase had better thermal stability than free laccase. The residual activity of immobilized laccase remained at about 50.0% after 30 days, which was 4.0 times that of free laccase. Immobilized laccase demonstrated excellent removal of phenolic pollutants (2,4-dichlorophenol, bisphenol A, phenol, and 4-chlorophenol) and perfect reusability with 70% removal efficiency retention for 2,4-dichlorophenol after seven cycles. These results suggested that immobilized laccase possessed great reusability, improved thermal stability, and excellent storage stability. Organic–inorganic nanomaterials have a good application prospect for laccase immobilization, and the immobilized laccase of this work may provide a practical application for the removal of phenolic pollutants.

关键词： polydopamine     pollutant removal     thermodynamic     phenolic pollutants     immobilized laccase    

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Cofactor engineering in cyanobacteria to overcome imbalance between NADPH and NADH: A mini review

Jongmoon Park,Yunnam Choi

《化学科学与工程前沿（英文）》 2017年 第11卷 第1期   页码 66-71 doi: 10.1007/s11705-016-1591-1

摘要： Cyanobacteria can produce useful renewable fuels and high-value chemicals using sunlight and atmospheric carbon dioxide by photosynthesis. Genetic manipulation has increased the variety of chemicals that cyanobacteria can produce. However, their uniquely abundant NADPH-pool, in other words insufficient supply of NADH, tends to limit their production yields in case of utilizing NADH-dependent enzyme, which is quite common in heterotrophic microbes. To overcome this cofactor imbalance and enhance cyanobacterial fuel and chemical production, various approaches for cofactor engineering have been employed. In this review, we focus on three approaches: (1) utilization of NADPH-dependent enzymes, (2) increasing NADH production, and (3) changing cofactor specificity of NADH-dependent enzymes from NADH to NADPH.

关键词： NADH-dependent enzyme     NADPH-dependent enzyme     transhydrogenase     site-directed mutagenesis     enzyme engineering    

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The influence of curing conditions on the mechanical properties and leaching of inorganic polymers made

Remus I. Iacobescu, Valérie Cappuyns, Tinne Geens, Lubica Kriskova, Silviana Onisei, Peter T. Jones, Yiannis Pontikes

《化学科学与工程前沿（英文）》 2017年 第11卷 第3期   页码 317-327 doi: 10.1007/s11705-017-1622-6

摘要： This study reports on the impact of the curing conditions on the mechanical properties and leaching of inorganic polymer (IP) mortars made from a water quenched fayalitic slag. Three similar IP mortars were produced by mixing together slag, aggregate and activating solution, and cured in three different environments for 28 d: a) at 20 °C and relative humidity (RH) ~ 50% (T20RH50), b) at 20 °C and RH≥90% (T20RH90) and c) at 60 °C and RH ~ 20% (T60RH20). Compressive strength (EN 196-1) varied between 19 MPa (T20RH50) and 31 MPa (T20RH90). This was found to be attributed to the cracks formed upon curing. Geochemical modelling and two leaching tests were performed, the EA NEN 7375 tank test, and the BS EN 12457-1 single batch test. Results show that Cu, Ni, Pb, Zn and As leaching occurred even at high pH, which varied between 10 and 11 in the tank test’s leachates and between 12 and 12.5 in the single batch’s leachates. Leaching values obtained were below the requirements for non-shaped materials of Flemish legislation for As, Cu and Ni in the single batch test.

关键词： inorganic polymer     geochemical leaching modelling     heavy metals     recycling     non-ferrous fayalitic slag     curing    

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Enhanced charge extraction for all-inorganic perovskite solar cells by graphene oxide quantum dots modified

《化学科学与工程前沿（英文）》 2023年 第17卷 第5期   页码 516-524 doi: 10.1007/s11705-022-2238-z

摘要： All-inorganic cesium lead bromide (CsPbBr3) perovskite solar cells have been attracting growing interest due to superior performance stability and low cost. However, low light absorbance and large charge recombination at TiO2/CsPbBr3 interface or within CsPbBr3 film still prevent further performance improvement. Herein, we report devices with high power conversion efficiency (9.16%) by introducing graphene oxide quantum dots (GOQDs) between TiO2 and perovskite layers. The recombination of interfacial radiation can be effectively restrained due to enhanced charge transfer capability. GOQDs with C-rich active sites can involve in crystallization and fill within the CsPbBr3 perovskite film as functional semiconductor additives. This work provides a promising strategy to optimize the crystallization process and boost charge extraction at the surface/interface optoelectronic properties of perovskites for high efficient and low-cost solar cells.

关键词： all inorganic     perovskite solar cells     graphene oxide quantum dots     high performance     stability    

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标题 作者 时间 类型 操作

Construction of a CaHPO4-PGUS1 hybrid nanoflower through protein-inorganic self-assembly, and its application

Tian Jiang, Yuhui Hou, Tengjiang Zhang, Xudong Feng, Chun Li

期刊论文

Diffusion process in enzyme–metal hybrid catalysts

期刊论文

Self-assembly of metal-cholesterol oxidase hybrid nanostructures and application in bioconversion of

Yu Xin, Qiuyue Gao, Yu Gu, Mengyao Hao, Guangming Fan, Liang Zhang

期刊论文

Designer enzyme for green materials innovation: Lactate-polymerizing enzyme as a key catalyst

Seiichi Taguchi

期刊论文

Formation of secondary inorganic aerosol in a frigid urban atmosphere

期刊论文

Influence of glucose feeding on the ligninolytic enzyme production of the white-rot fungus Phanerochaete

ZHOU Xiaoyan, WEN Xianghua, FENG Yan

期刊论文

Detection of Escherichia coli in wastewater based on enzyme immunoassay

XI Haiyan, CAI Qiang, HE Miao, SHI Hanchang

期刊论文

Enzyme@bismuth-ellagic acid: a versatile platform for enzyme immobilization with enhanced acid-base stability

期刊论文

Soil enzyme activities and their indication for fertility of urban forest soil

SHAN Qihua, YU Yuanchun, ZHANG Jinchi, YU Jian

期刊论文

Spectrokinetics study of probable effects of diverse inorganic ions on bleaching of dye

Rafia AZMAT, Masooda QADRI, Fahim UDDIN

期刊论文

Organic and inorganic phosphorus uptake by bacteria in a plug-flow microcosm

Jinbo ZHAO, Xuehua LIU

期刊论文

Immobilization of laccase on organic–inorganic nanocomposites and its application in the removal of phenolic

期刊论文

Cofactor engineering in cyanobacteria to overcome imbalance between NADPH and NADH: A mini review

Jongmoon Park,Yunnam Choi

期刊论文

The influence of curing conditions on the mechanical properties and leaching of inorganic polymers made

Remus I. Iacobescu, Valérie Cappuyns, Tinne Geens, Lubica Kriskova, Silviana Onisei, Peter T. Jones, Yiannis Pontikes

期刊论文

Enhanced charge extraction for all-inorganic perovskite solar cells by graphene oxide quantum dots modified

期刊论文