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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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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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Transcriptomic basis of neutrophil ratio variation induced by poly I:C stimulation in porcine peripheral

Haiyan WANG, Qiaoxia ZHANG, Lilin YIN, Xiangdong LIU, Shuhong ZHAO, Mengjin ZHU, Changchun LI

《农业科学与工程前沿（英文）》 2017年 第4卷 第3期   页码 342-352 doi: 10.15302/J-FASE-2017162

摘要： Neutrophils are vital components of defense mechanisms against invading pathogens and are closely linked with the individual antiviral capacity of pigs and other mammals. Neutrophilia is a well-known clinical characteristic of viral and bacterial infections. Using Affymetrix porcine genome microarrays, we investigated the gene expression profiles associated with neutrophil variation in porcine peripheral blood before and after polyriboinosinic-polyribocytidylic acid stimulation. Transcriptomic analysis showed 796 differentially expressed genes (DEGs) in extreme response (ER) pigs and 192 DEGs in moderate response (MR) pigs. Most DEGs were related to immune responses, included , , , , , , , and . Gene ontology analysis indicated that the DEGs of both ER and MR pigs were involved in common biological processes, such as cell proliferation, growth regulation, immune response, inflammatory response and cell activation. The ER and MR groups also showed differences in DEGs involved in biological processes. DEGs involved in cell division and cell cycle were specifically found in the ER pigs, whereas DEGs involved in cell migration were specifically found in the MR pigs. The study provides a basic understanding of the molecular basis for the antiviral capacity of pigs and other mammals.

关键词： neutrophil     peripheral blood     pig     poly I:C     transcriptome    

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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 acid

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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Poly(vinylidene fluoride--hexafluoro propylene) membranes prepared via thermally induced phase separation

《化学科学与工程前沿（英文）》 2022年 第16卷 第5期   页码 720-730 doi: 10.1007/s11705-021-2098-y

摘要： A non-toxic and environmentally safe diluent, acetyl tributyl citrate, was employed to prepare poly(vinylidene fluoride)-co-hexafluoropropylene membranes via thermally induced phase separation. Effects of the polymer concentration on the phase diagram, membrane morphology, hydrophobicity, pore size, porosity and mechanical properties (tensile stress and elongation at break) were investigated. The results showed that the pore size and porosity tended to decrease with increasing polymer concentration, whereas the contact angle, liquid entry pressure and mechanical properties showed the opposite trend. In direct contact membrane distillation operation with 3.5 wt-% sodium chloride solution as the feed solution, the prepared membranes performed high salt rejection (>99.9%). Furthermore, the prepared membranes retained excellent performance in long-term stability tests regarding the permeate flux and salt rejection.

关键词： poly(vinylidene fluoride)-co-hexafluoropropylene     thermally induced phase separation     non-toxic diluent     direct contact membrane distillation    

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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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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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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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Reuse of heavy metal-accumulating

Dongdong MA,Hongwen GAO

《环境科学与工程前沿（英文）》 2014年 第8卷 第6期   页码 952-959 doi: 10.1007/s11783-013-0619-8

摘要： Phytoremediation technology is regarded as a simple and efficient way to remove heavy metals from contaminated soil. A reasonable disposal of metal hyperaccumulators is always a major issue in waste reuse and resource-saving. The heavy metal-accumulating (L.) was investigated where heavy metals were desorbed by a facile acid-treatment. The result indicated that more than 90% of heavy metals (Zn, Pb and Cu) was extracted from with 0.2 mmol·L HCl. The plant residue was used to adsorb heavy metals ions. The adsorption fitted the Langmuir isotherm model with the saturation adsorption capacity of 9.5 mg·g Zn , 36.2 mg·g Pb and 12.9 mg·g Cu , and the surface complexation and the backfilling of heavy metal-imprinting cavities existed simultaneously during the adsorption. The treatment of wastewaters indicated that the plant residue exhibited a high removal rate of 97% for Cu. Also, the material could be recycled. The method offers a new disposal approach for heavy metal hyperaccumulator.

关键词： heavy metals     Cynondon dactylon     acid-treatment     adsorption     recycling    

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Effect of polyethylene glycol on the crystallization, rheology and foamability of poly(lactic acid) containing

《化学科学与工程前沿（英文）》 2023年 第17卷 第12期   页码 2074-2087 doi: 10.1007/s11705-023-2342-8

摘要： In this study, the rheological properties, crystallization and foaming behavior of poly(lactic acid) with polyamide 6 nanofibrils were examined with polyethylene glycol as a compatibilizer. Polyamide 6 particles were deformed into nanofibrils during drawing. For the 10% polyamide 6 case, polyethylene glycol addition reduced the polyamide 6 fibril diameter from 365.53 to 254.63 nm, owing to the smaller polyamide 6 particle size and enhanced interface adhesion. Rheological experiments revealed that the viscosity and storage modulus of the composites were increased, which was associated with the three-dimensional entangled network of polyamide 6 nanofibrils. The presence of higher aspect ratio polyamide 6 nanofibrils substantially enhanced the melt strength of the composites. The isothermal crystallization kinetics results suggested that the polyamide 6 nanofibrils and polyethylene glycol had a synergistic effect on accelerating poly(lactic acid) crystallization. With the polyethylene glycol, the crystallization half-time reduced from 103.6 to 62.2 s. Batch foaming results indicated that owing to higher cell nucleation efficiency, the existence of polyamide 6 nanofibrils led to a higher cell density and lower expansion ratio. Furthermore, the poly(lactic acid)/polyamide 6 foams exhibited a higher cell density and expansion ratio than that of the foams without polyethylene glycol.

关键词： poly(lactic acid)     foaming     microfibrillation     rheological property     crystallization    

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Anodic oxidation of azo dye C.I. Acid Red 73 by the yttrium-doped Ti/SnO

Li XU, Zhi GUO, Lishun DU

《化学科学与工程前沿（英文）》 2013年 第7卷 第3期   页码 338-346 doi: 10.1007/s11705-013-1335-4

摘要： This work was conducted to study the ability of anodic oxidation of azo dye C.I. Acid Red 73 (AR73) using the yttrium-doped Ti/SnO -Sb electrodes. The effects of Sb doping level, yttrium doping level, thermal decomposition temperature and cycle times of dip-coating thermal decomposition on the properties of the electrodes were investigated. The results showed that the excellent electrochemical activity of Ti/SnO -Sb-Y electrode can be achieved at a 7∶1 molar ratio of Sn∶Sb and thermal decomposition temperature of 550°C. Moreover when the cycle times of dip-coating and thermal decomposition were up to 10 times, the performance of the electrode tends to be stable. The Ti/SnO -Sb electrodes doped with yttrium (0.5 mol-%) showed the most excellent electrochemical activity. In addition, the influences of operating variables, including current density, initial pH, dye concentration and support electrolyte, on the colour removal, chemical oxygen demand (COD) removal and current efficiency were also investigated. Our results confirmed that the current efficiency increased with the concentrations of dye and sodium chloride. Moreover, increasing the current density and the initial pH would reduce the current efficiency.

关键词： SnO2-Sb     yttrium doping     anodic oxidation     azo dyes    

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标题 作者 时间 类型 操作

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

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

Transcriptomic basis of neutrophil ratio variation induced by poly I:C stimulation in porcine peripheral

Haiyan WANG, Qiaoxia ZHANG, Lilin YIN, Xiangdong LIU, Shuhong ZHAO, Mengjin ZHU, Changchun LI

期刊论文

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 acid

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

期刊论文

Poly(vinylidene fluoride--hexafluoro propylene) membranes prepared via thermally induced phase separation

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

Enhanced production of

Shen Huang,Xudong Feng,Chun Li

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

Reuse of heavy metal-accumulating

Dongdong MA,Hongwen GAO

期刊论文

Effect of polyethylene glycol on the crystallization, rheology and foamability of poly(lactic acid) containing

期刊论文

Anodic oxidation of azo dye C.I. Acid Red 73 by the yttrium-doped Ti/SnO

Li XU, Zhi GUO, Lishun DU

期刊论文