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Functional characterization of caffeic acid

Fengyan WU, Zhenying WU, Aiguo YANG, Shanshan JIANG, Zeng-Yu WANG, Chunxiang FU

《农业科学与工程前沿（英文）》 2018年 第5卷 第1期   页码 98-107 doi: 10.15302/J-FASE-2017198

摘要： Caffeic acid -methyltransferase (COMT) is a crucial enzyme that mainly methylates phenylpropanoid -hydroxyl of C in the biosynthesis of syringyl lignin in angiosperms. A putative , named as , was isolated from switchgrass ( ), a C warm-season dual-purpose forage and bioenergy crop. Our results showed that recombinant PvCOMT1 enzyme protein catalyzed the methylation of 5-OH coniferyl alcohol, 5-OH coniferaldehyde (CAld5H) and 5-OH ferulic acid. Further studies indicate that CAld5H can dominate COMT-mediated reactions by inhibiting the methylation of the other substrates. Transgenic switchgrass plants generated by an RNAi approach were further employed to study the function of in internode lignification. A dramatic decrease in syringyl lignin units coupled with an obvious incorporation in 5-OH guaiacyl lignin units were observed in the COMT-RNAi transgenic plants. However, the constitutive suppression of COMT in switchgrass plants altered neither the pattern of lignin deposition along the stem nor the anatomical structure of internodes. Consistent with the biochemical characterization of PvCOMT1, a significant decrease in sinapaldehyde was found in the COMT-RNAi transgenic switchgrass plants, suggesting that CAld5H could be the optimal intermediate in the biosynthesis syringyl lignin.

关键词： biofuel crop     caffeic acid O-methyltransferase     forage     lignin     Panicum virgatum     switchgrass     transgenic plant    

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PGUS1 hybrid nanoflower through protein-inorganic self-assembly, and its application in glycyrrhetinic acid3-O-mono-β-D-glucuronide preparation

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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Genomic and metabolomic analysis of with enhanced poly--glutamic acid production through atmospheric

《化学科学与工程前沿（英文）》 2022年 第16卷 第12期   页码 1751-1760 doi: 10.1007/s11705-022-2211-x

摘要： Poly-γ-glutamic acid is an extracellular polymeric substance with various applications owing to its valuable properties of biodegradability, flocculating activity, water solubility, and nontoxicity. However, the ability of natural strains to produce poly-γ-glutamic acid is low. Atmospheric and room temperature plasma was applied in this study to conduct mutation breeding of Bacillus licheniformis CGMCC 2876, and a mutant strain M32 with an 11% increase in poly-γ-glutamic acid was obtained. Genome resequencing analysis identified 7 nonsynonymous mutations of ppsC encoding lipopeptide synthetase associated with poly-γ-glutamic acid metabolic pathways. From molecular docking, more binding sites and higher binding energy were speculated between the mutated plipastatin synthase subunit C and glutamate, which might contribute to the higher poly-γ-glutamic acid production. Moreover, the metabolic mechanism analysis revealed that the upregulated amino acids of M32 provided substrates for glutamate and promoted the conversion between L- and D-glutamate acids. In addition, the glycolytic pathway is enhanced, leading to a better capacity for using glucose. The maximum poly-γ-glutamic acid yield of 14.08 g·L–1 was finally reached with 30 g·L–1 glutamate.

关键词： ARTP mutagenesis     Bacillus licheniformis     poly-γ-glutamic acid     metabolomics    

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通过<i> B i>位Ta置换对<i> AB i> O4型EuNbO4的热学和力学性质进行优化 Article

陈琳, 冯晶

《工程（英文）》 2020年 第6卷 第2期   页码 177-184 doi: 10.1016/j.eng.2019.12.006

摘要：

铁弹性的ABO4型RETaO4陶瓷和RENbO4陶瓷（RE表示稀土）是具有潜在应用价值的热障涂层（TBC）材料，

关键词： 热障涂层，稀土铌酸盐，置换，热导率，热膨胀系数，杨氏模量    

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H2 对Pt-Ba-Ce /γ-Al2O3 催化剂NO<i>xi> 存储和还原机理的影响研究 Article

王攀, 裔静, 孙川, 罗鹏, 雷利利

《工程（英文）》 2019年 第5卷 第3期   页码 568-575 doi: 10.1016/j.eng.2019.02.005

摘要：

本研究采用浸渍法制备了Pt-Ba-Ce/γ-Al2O3催化剂，利用实验评价了H2 对NSR（NOx storage and reduction）催化剂存储和还原机理的影响，并采用综合表征技术研究了Pt-Ba-Ce /γ-Al2O3x、CeO2 和BaCO3 峰很好地分散在γ-Al2O<

关键词： Pt–Ba–Ce/γ-Al2O3 催化剂，物理化学性质，NO<i>xi>存储和还原，NO<i>xi> 排放    

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On the monolayer dispersion behavior of Co3O4 on HZSM-5 support: designing applicable

《化学科学与工程前沿（英文）》 2023年 第17卷 第11期   页码 1741-1754 doi: 10.1007/s11705-023-2332-x

摘要： Based on monolayer dispersion theory, Co3O4/ZSM-5 catalysts with different loadings have been prepared for selective catalytic reduction of nitrogen oxides by ammonia. Co3O4 can spontaneously disperse on HZSM-5 support with a monolayer dispersion threshold of 0.061 mmol 100 m–2, equaling to a weight percentage around 4.5%. It has been revealed that the quantities of surface active oxygen (O2–) and acid sites are crucial for the reaction, which can adsorb and activate NOx and NH3 reactants effectively. Below the monolayer dispersion threshold, Co3O4 is finely dispersed as sub-monolayers or monolayers and in an amorphous state, which is favorable to generate the two kinds of active sites, hence promoting the performance of ammonia selective catalytic reduction of nitrogen oxide. However, the formation of crystalline Co3O4 above the capacity is harmful to the reaction performance. 4% Co3O4/ZSM-5, the catalyst close to the monolayer dispersion capacity, possesses the most abundant active O2– species and acidic sites, thereby demonstrating the best reaction performance in all the samples. It is proposed the optimal Co3O4/ZSM-5 catalyst can be prepared by loading the capacity amount of Co3O4 onto HZSM-5 support.

关键词： Co3O4/ZSM-5     NOx-SCR by NH3     monolayer dispersion threshold effect     surface acid sites     surface active O2– anions    

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><i>In situi> growth of phosphorized ZIF-67-derived amorphous CoP/Cu2O@CF electrocatalyst

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1430-1439 doi: 10.1007/s11705-023-2320-1

摘要： Transition metal phosphides have been extensively studied for catalytic applications in water splitting. Herein, we report an in situ phosphorization of zeolitic imidazole frameworks (ZIF-67) to generate amorphous cobalt phosphide/ZIF-67 heterojunction on a self-supporting copper foam (CF) substrate with excellent performance for hydrogen evolution reaction (HER). The needle-leaf like copper hydroxide was anchored on CF surface, which acted as implantation to grow ZIF-67. The intermediate product was phosphorized to obtain final electrocatalyst (CoP/Cu2O@CF) with uniform particle size, exhibiting a rhombic dodecahedron structure with wrinkles on the surface. The electrochemical measurement proved that CoP/Cu2O@CF catalyst exhibited excellent HER activity and long-term stability in 1.0 mol·L–1 KOH solution. The overpotential was only 62 mV with the Tafel slope of 83 mV·dec–1 at a current density of 10 mA·cm–2, with a large electrochemical active surface area. It also showed competitive performance at large current which indicated the potential application to industrial water electrolysis to produce hydrogen. First-principle calculations illustrated that benefit from the construction of CoP/ZIF-67 heterojunction, the d-band center of CoP downshifted after bonding with ZIF-67 and the Gibbs free energy (ΔGH*) changed from –0.18 to –0.11 eV, confirming both decrease in overpotential and excellent HER activity. This work illustrates the efficient HER activity of CoP/Cu2O@CF catalyst, which will act as a potential candidate for precious metal electrocatalysts.

关键词： CoP/Cu2O@CF     electrocatalyst     phosphorization     HER     DFT    

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New perspectives in free nitrous acid (FNA) uses for sustainable wastewater management

《环境科学与工程前沿（英文）》 2023年 第18卷 第2期 doi: 10.1007/s11783-024-1786-5

摘要：

● The historical development of free nitrous acid (FNA) technologies is reviewed.

关键词： Free nitrous acid     Acid-tolerant ammonia oxidizer     In situ generation     Wastewater management    

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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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Design of nanocarriers for efficient cellular uptake and endosomal release of small molecule and nucleic acid

Vaibhav Mundra, Ram I. Mahato

《化学科学与工程前沿（英文）》 2014年 第8卷 第4期   页码 387-404 doi: 10.1007/s11705-014-1457-3

摘要： There are many challenges in developing efficient and target specific delivery systems of small molecule and nucleic acid drugs. Cell membrane presents one of the major barriers for the penetration of hydrophilic macromolecules across the plasma membrane. Nanocarriers have been designed to enhance their cellular uptake via endocytosis but following their cellular uptake, endosomal escape is the rate limiting step which restricts the value associated with the enhanced uptake by nanocarriers. Viruses are an excellent model for efficient cytosolic delivery by nanocarriers. Viruses exploit intracellular cues to release the genome to cytosol. In this review, we first discuss different endocytic uptake pathways and endosomal escape mechanisms. We then summarize the existing tools for studying the intracellular trafficking of nanocarriers. Finally, we highlight the important design elements of recent virus-based nanocarriers for efficient cellular uptake and endosomal escape.

关键词： nanocarrier     cellular uptake     endosomal release     nucleic acid drug    

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Anefficient data layout scheme for better I/O balancing inRAID-6 storage systems

Ping XIE,Jian-zhong HUANG,Er-wei DAI,Qiang CAO,Chang-sheng XIE

《信息与电子工程前沿（英文）》 2015年 第16卷 第5期   页码 335-345 doi: 10.1631/FITEE.1400362

摘要： Among redundant arrays of independent disks (RAID)-6 codes, maximum distance separable (MDS) based RAID-6 codes are popular because they have the optimal storage efficiency. Although vertical MDS codes exhibit better load balancing compared to horizontal MDS codes in partial stripes, an I/O unbalancing problem still exists in some vertical codes. To address this issue, we propose a novel efficient data layout, uniform P-code (UPC), to support highly balanced I/Os among P-coded disk arrays (i.e., PC). In UPC, the nonuniformly distributed information symbols in each parity chain of P-code are moved along their columns to other rows, thus enabling the parity chain to keep original parity relationships and tolerate double disk failures. The UPC scheme not only achieves optimal storage efficiency, computational complexity, and update complexity, but also supports better I/O balancing in the context of large-scale storage systems. We also conduct a performance study on reconstruction algorithms using an analytical model. Besides extensive theoretical analysis, comparative performance experiments are conducted by replaying real-world workloads under various configurations. Experimental results illustrate that our UPC scheme significantly outperforms the PC scheme in terms of average user response time. In particular, in the case of a 12-disk array, the UPC scheme can improve the access performance of the RAID-6 storage system by 29.9% compared to the PC scheme.

关键词： RAID-6     Data availability     High performance     I/O balancing    

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Enhanced production of

Shen Huang,Xudong Feng,Chun Li

《化学科学与工程前沿（英文）》 2015年 第9卷 第4期   页码 501-510 doi: 10.1007/s11705-015-1544-0

摘要： -Glucuronidase from Li-3 (PGUS) can efficiently hydrolyze glycyrrhizin into the more valuable glycyrrhetic acid monoglucuronide. However, a low productivity of PGUS and the lack of an effective separation strategy have significantly limited its industrial applications. Therefore, the production of PGUS has been improved by optimizing both the fermentation and purification strategies. A two-stage fermentation strategy was developed where PGUS was first grown with glucose and then PGUS was produced in the presence of glycyrrhizin as an inducer. By using this strategy, the biomass was increased 1.5 times and the PGUS activity increased 5.4 times compared to that when glycyrrhizin was used as the sole carbon source. The amount of PGUS produced was increased another 16.6% when the fermentation was expanded to a 15-L fermenter. An effective protocol was also established to purify the PGUS using a sequential combination of hydrophobic, strong anion-exchange and gel filtration chromatography. This protocol had a recovery yield of 6% and gave PGUS that was 39 times purer than the crude PGUS. The purified PGUS had a specific activity of 350 U·mg .

关键词： β-glucuronidase     glycyrrhetic acid monoglucuronide     cell disruption     purification     chromatography    

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Deposition of copper nanoparticles on multiwalled carbon nanotubes modified with poly (acrylic acid)

Li SHENG,Shuhang HUANG,Minghao SUI,Lingdian ZHANG,Lei SHE,Yong CHEN

《环境科学与工程前沿（英文）》 2015年 第9卷 第4期   页码 625-633 doi: 10.1007/s11783-014-0711-8

摘要： A novel hybrid material, Cu-PAA/MWCNTs (copper nanoparticles deposited multiwalled carbon nanotubes with poly (acrylic acid) as dispersant, was prepared and expected to obtain a more effective and well-dispersed disinfection material for water treatment. X-ray energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), the X-ray fluorescence (XRF), X-ray photoelectron spectra (XPS), Fourier transform infrared spectra (FT-IR), Raman spectroscopy, and thermal gravimetric analyzer (TGA) were used to characterize the Cu-PAA/MWCNTs. ( ) was employed as the target bacteria. The cell viability determination and fluorescence imaging results demonstrated that Cu-PAA/MWCNTs possessed strong antimicrobial ability on . The deposited Cu was suggested to play an important role in the antimicrobial action of Cu-PAA/MWCNTs.

关键词： multiwalled carbon nanotubes     copper nanoparticles     antimicrobial activity     Escherichia coli (E. coil)    

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富含<i>sni>-2 DHA脂质对大脑的益处及其酶法合成综述 Review

金俊, 金青哲, 王兴国, Casimir C. Akoh

《工程（英文）》 2020年 第6卷 第4期   页码 424-431 doi: 10.1016/j.eng.2020.02.009

摘要：

大脑中二十二碳六烯酸（DHA, ω-3脂肪酸）的含量与中枢神经系统的正常发育和功能维持高度相关。甘油酯sn-2位上的DHA可以被肠黏膜更好地吸收，从而实现机体对DHA的高效利用。然而，如今人们在饮食中摄入较多的饱和脂肪或富含ω-6脂肪酸的油脂，而摄入较少的DHA，从而导致了部分个体在行为和神经生理学方面的缺陷。为了全面了解DHA对大脑的有益功能，本文系统介绍了天然油脂甘油骨架上DHA的位置分布（sn-2和sn-1,3位）特征，并讨论了DHA补充和通过肠-脑轴传递信息的潜在功能机制。肠-脑轴包含的多条双向信息通道为DHA、肠道菌群和大脑健康的相互作用提供了新的研究思路。为了在日常饮食中摄入更多的sn-2 DHA，我们建议通过更为高效和经济的酯交换制造技术生产富含sn-2 DHA脂质，其中需要解决的关键技术包括强化酶的特异性和优化纯化工艺。这类饮食可满足对sn-2 ω-3脂质有强烈需求的人群，特别是婴儿、儿童、孕妇和哺乳期妇女。

关键词： DHA 和 sn-2 DHA     单甘酯     大脑     肠-脑轴     结构脂质    

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High production of butyric acid by

Chao Ma,Jianfa Ou,Matthew Miller,Sarah McFann,Xiaoguang (Margaret) Liu

《化学科学与工程前沿（英文）》 2015年 第9卷 第3期   页码 369-375 doi: 10.1007/s11705-015-1525-3

摘要： The objective of this study was to improve the production of butyric acid by process optimization using the metabolically engineered mutant of (PAK-Em). First, the free-cell fermentation at pH 6.0 produced butyric acid with concentration of 38.44 g/L and yield of 0.42 g/g. Second, the immobilized-cell fermentations using fibrous-bed bioreactor (FBB) were run at pHs of 5.0, 5.5, 6.0, 6.5 and 7.0 to optimize fermentation process and improve the butyric acid production. It was found that the highest titer of butyric acid, 63.02 g/L, was achieved at pH 6.5. Finally, the metabolic flux balance analysis was performed to investigate the carbon rebalance in . The results show both gene manipulation and fermentation pH change redistribute carbon between biomass, acetic acid and butyric acid. This study demonstrated that high butyric acid production could be obtained by integrating metabolic engineering and fermentation process optimization.

关键词： Clostridium tyrobutyricum     butyric acid production     fermentation     mutant     pH     flux balance analysis    

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标题 作者 时间 类型 操作

Functional characterization of caffeic acid

Fengyan WU, Zhenying WU, Aiguo YANG, Shanshan JIANG, Zeng-Yu WANG, Chunxiang FU

期刊论文

PGUS1 hybrid nanoflower through protein-inorganic self-assembly, and its application in glycyrrhetinic acid3-O-mono-β-D-glucuronide preparation

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

期刊论文

Genomic and metabolomic analysis of with enhanced poly--glutamic acid production through atmospheric

期刊论文

通过<i> B i>位Ta置换对<i> AB i> O4型EuNbO4的热学和力学性质进行优化

陈琳, 冯晶

期刊论文

H2 对Pt-Ba-Ce /γ-Al2O3 催化剂NO<i>xi> 存储和还原机理的影响研究

王攀, 裔静, 孙川, 罗鹏, 雷利利

期刊论文

On the monolayer dispersion behavior of Co3O4 on HZSM-5 support: designing applicable

期刊论文

><i>In situi> growth of phosphorized ZIF-67-derived amorphous CoP/Cu2O@CF electrocatalyst

期刊论文

New perspectives in free nitrous acid (FNA) uses for sustainable wastewater management

期刊论文

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

期刊论文

Design of nanocarriers for efficient cellular uptake and endosomal release of small molecule and nucleic acid

Vaibhav Mundra, Ram I. Mahato

期刊论文

Anefficient data layout scheme for better I/O balancing inRAID-6 storage systems

Ping XIE,Jian-zhong HUANG,Er-wei DAI,Qiang CAO,Chang-sheng XIE

期刊论文

Enhanced production of

Shen Huang,Xudong Feng,Chun Li

期刊论文

Deposition of copper nanoparticles on multiwalled carbon nanotubes modified with poly (acrylic acid)

Li SHENG,Shuhang HUANG,Minghao SUI,Lingdian ZHANG,Lei SHE,Yong CHEN

期刊论文

富含<i>sni>-2 DHA脂质对大脑的益处及其酶法合成综述

金俊, 金青哲, 王兴国, Casimir C. Akoh

期刊论文

High production of butyric acid by

Chao Ma,Jianfa Ou,Matthew Miller,Sarah McFann,Xiaoguang (Margaret) Liu

期刊论文