3 Biotech
·
2018
·Vol. 8
·期 7
·1-9
·
IF 1.497
Huang Jian-Feng,Zhang Bo,Shen Zhen-Yang,Liu Zhi-Qiang,Zheng Yu-Guo
O -succinyl- l -homoserine (OSH) is a promising platform chemical for the production of C4 chemicals with huge market potential which can be produced by fermentation from glucose. To construct a strain capable of producing OSH with high yield, the metJ (encodes transcriptional repressor) and metI (encodes a subunit of dl -methionine transporter) were deleted in Escherichia coli W3110 to obtain a strain E. coli ∆JI. Then, overexpression of metL (encodes bifunctional aspartate kinase/homoserine dehydrogenase II) and inactivation of metB (encodes cystathionine γ-synthase) were implemented in one step, and the OSH titer of the resulting strain E. coli ∆JIB * Trc metL was dramatically increased to 7.30 g/L. The feedback regulation was further relieved by progressively overexpressing metA fbr (encodes homoserine O -succinyltransferase), yjeH (encodes l -methionine exporter), and thrA fbr (encodes bifunctional aspartate kinase/homoserine dehydrogenase I) to increase the metabolic flux from aspartate to OSH. The 100% rationally designed strain E. coli ∆JIB * Trc metL /pTrc- metA fbr -Trc- thrA fbr - yjeH produced 9.31 g/L OSH from 20 g/L glucose (0.466 g/g glucose) in batch fermentation, which represents the highest OSH yield from glucose reported to date. The culture profiles of the newly constructed strains were recorded to investigate their productive properties. The effects of l -methionine addition on the fermentation process of the optimal strain were also studied. Our results demonstrate that tuning the expression level of metL , inactivation of metB , and attenuation of feedback resistance of the crucial enzymes in the biosynthetic pathway are the key factors that impact the OSH production in E. coli .
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Green Processing and Synthesis
·
2019
·Vol. 8
·期 1
·667-676
·
IF 1.128
Dan Chen,Binglin Li,Bin Li,Xiaoli Zhang,Longhui Wei,Wenwen Zheng
Catalytic efficiency in synthesis of vitamin E succinate was dramatically increased via the preparation of robust catalyst and the improvement of reaction system. 4-dimethylaminopyridine (DMAP) was covalently immobilized on nano-SiO 2 to avoid the catalyst contamination of the product and permit the easy recycling of DMAP. Then, a hexane-acetone mixed solvent system was firstly introduced to replace the traditional single-solvent system, which was employed to improve the activity of immobilized DMAP derivative and the substrate solubility of the reaction system. The highest vitamin E succinate yield of 94% was achieved. In addition, the recyclability and stability of the immobilized DMAP derivative was excellent, the yield of vitamin E succinate had no obvious loss and remained 90% after recycling 20 times. The excellent results make this technology be a promising candidate for the industrial production of vitamin E succinate.
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ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Yujuan Xu,Wu Lei,Juan Su,Jinjin Hu,Xiaodan Yu,Tong Zhou,Yun Yang,Daniel Mandler,Qingli Hao
A fast, ultrasensitive electrochemical sensing platform based on graphitic carbon nitride-electrochemically deposited-poly(3,4-ethylenedioxythiophene) (g-C 3 N 4 -E-PEDOT) composite was constructed by in-situ electropolymerization and applied for the quantitative determination of acetaminophen (AP). E-PEDOT was introduced as the conducting matrix for developing g-C 3 N 4 composite to complement the poor conductivity disadvantage of g-C 3 N 4 . The strong affinity and synergetic effect between g-C 3 N 4 and E-PEDOT, which were analyzed by PM6 computational calculation, highly improved the electron transfer property and remarkably enhanced the electrochemical catalytic activity of the composite. The g-C 3 N 4 -E-PEDOT modified glassy carbon electrode (GCE) demonstrated better electrocatalytic activity towards the oxidation of AP than bare, g-C 3 N 4 and E-PEDOT modified ones. Under the optimized conditions, the oxidation peak currents at the g-C 3 N 4 -E-PEDOT/GCE increased linearly in the concentration range of AP from 0.01 to 2 μM and 2–100 μM, and an ultra-low limit of detection (LOD) of 34.28 nM was obtained (S/N = 3). In addition, the g-C 3 N 4 -E-PEDOT/GCE was successfully applied for the AP determination in the clinical human serum, and also exhibited excellent selectivity, reproducibility and stability. Except the novel AP determination approach, moreover, this work provided a new electrochemical application angle of graphitic carbon nitride theoretically as well as experimentally.
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JOURNAL OF FOOD SCIENCE
·
2024
·Vol. 89
·期 12
·9271-9282
·
IF 3.2
Jiayue Zhou,Dong Li,Yanqun Xu,Xiaochen Zhang,Lei Wang,Lin Zhou,Liang Zou,Zisheng Luo
( E )-2-Hexenal (E2H) is an important volatile organic compound (VOC) that can serve as a marker for fruit quality sensing and shelf-life evaluation. However, visual and portable sensors for E2H have not been reported mainly because of the difficulty in selective response to E2H while avoiding interference from other VOC, especially isomers. Herein, we developed a novel colorimetric sensor based on thiol-functionalized polydiacetylene assembly (PDA-SH/PDA) for the quantitative and selectivity of E2H. The mechanism was that E2H underwent a Michael addition reaction with sulfhydryl groups in PDA-SH/PDA. The Michael addition reaction destroyed the hydrogen bond and distorted the conjugated molecular system, resulting in colorimetric responses. Under optimal conditions, a good linear relationship was observed between E2H concentration and red colorimetric shift ( R 2 = 0.9679). The E2H sensor yields a high analytical sensitivity of 1.5203% and a limit of detection of 0.015 g L −1 . Besides, the PDA-SH/PDA sensor can be used to visually distinguish E2H and its isomer ( Z )-3-hexenal. The PDA-SH/PDA sensor yielded a statistically significant difference in red colorimetric shift ( p < 0.01) between the pairs of isomers in the ripeness of fruits. At last, the sensor was utilized for detecting E2H in grapes from different shelf lives. We found that the E2H concentration increased from 66.16 ± 1.54 to 67.56 ± 1.30 µg L −1 as storage time was prolonged. The results of this research not only demonstrated the feasibility of visual and on-site detection of E2H but also provided potential promise for portable fruit quality sensing and shelf-life evaluation.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2014
·
IF 3.107
Dong-Mei Wang,Cheng-Chen Zhang,Qiang Zhang,Nusrat Shafiq,Gennaro Pescitelli,Deng-Wu Li,Jin-Ming Gao
Five new sesquiterpene polyol esters with a dihydro-β-agarofuran skeleton, designated as wightianines A–E (1–5), besides two known compounds, were isolated from the methanolic extract of the whole plant of the traditional herbal medicine Parnassia wightiana Wall. The structures of the isolated compounds were elucidated on the basis of spectroscopic analyses, including two-dimensional nuclear magnetic resonance techniques (correlation spectroscopy, heteronuclear multiple-quantum coherence, nuclear Overhauser effect spectrometry, and heteronuclear multiple-bond correlation) and electronic circular dichroism studies. The antifungal and insecticidal activities of five compounds were evaluated against several plant pathogenic fungi and armyworm larvae (Mythimna separata Walker). Among the test metabolites, compounds 2 and 7 both exhibited potent antifungal activity against the phytopathogenic fungus Cytospora sp. with minimum inhibitory concentration values of 0.78 μg/mL, which are equal to the two positive controls, hymexazol and carbendazim. However, no insecticidal activity of the test compounds was observed in the present study. Compounds 2 and 7 could be promising leads for developing new fungicides against agriculturally important fungus Cytospora sp.
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CHINESE JOURNAL OF CATALYSIS
·
2013
·
IF 1.304
Yi Hu,Xiangjun Jiang,Suwen Wu,Ling Jiang,He Huang
Vitamin E succinate was synthesized by interfacial activated Candida rugosa lipase (CRL) encapsulated in sol-gel materials. The effects of various immobilization parameters were investigated. The optimum conditions were found to consist of n -propyltrimethoxysilane/tetraethoxysilane molar ratio = 1/1, water/silane molar ratio ( R value) = 20, lipase loading = 0.5 mg/ml sol, and PEG400 loading = 12 μl/ml sol. Compared with free enzymes, sol-gel encapsulated enzymes kept its activity of 70.58% and achieved 2.6-fold increased stability after 18 h incubation in phosphate buffer (0.025 mol/L, pH = 7.0) at 50 °C. Based on the interfacial characteristics of CRL, five kinds of surfactants were used for activation. The results demonstrate that olive oil was the most effective in activating CRL. The esterification activity of vitamin E succinate synthesis by interfacial activated CRL encapsulated in sol-gel materials reached up to 6.7-fold and 1.43-fold that of free enzyme and non-interfacial activated enzyme, respectively.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Qing Luo,Chenyue Yan,Ruoteng Ma,Lei Dai,Wenjun Shu,Anum Asghar,Zhigang Jia,Xulong Zhu,Shun Yu
The development of multifunctional hydrogels, especially hydrogels with antibacterial and antioxidant properties, plays a crucial role in the effective healing of diabetic wounds. This work proposed a novel composite hydrogel with the oxidized gellan gum (O-GG) and hyaluronic acid (HA) as the hydrogel matrix, and the crosslinking was realized via the Ca 2+ . ε-polylysine/MnO 2 nanozymes (EM) offered antioxidant and antibacterial properties to the corresponding composite hydrogels. The results verified that the O-GG/HA@EM hydrogel exhibited excellent cytocompatibility and injectability. The CCK-8 data indicated that the proliferation rate of mouse fibroblasts reached 314.58 % after three days of coculture with the hydrogel. The hydrogel effectively alleviated oxidative stress and hypoxic microenvironments in wounds, inhibited bacterial infection, and promoted angiogenesis, thereby significantly accelerating the healing process of diabetic wounds. Data from a mouse diabetic wound model revealed that the wound closure rate in the sample group reached 92.4 % after 14 days. This composite hydrogel provides a novel and effective solution for the treatment of chronic diabetic wounds.
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ACS Applied Electronic Materials
·
2024
·
IF 4.3
Qiaoqiao Bai,Xin Liu,Xiaohu Shi,Ziwei Wang,Ziyi Wu,Qizhi Dong,Nan Liu,Tang Liu,Song Liu
With the rapid development of technologies, such as the Internet of Things and artificial intelligence, the flexible electronic skin (e-skin) that bridges the material and the physical world presents vast market potential. However, the development of cost-effective, multifunctional e-skin remains a formidable challenge. Herein, a dual-functional e-skin based on a microspinous MXene/PDMS composite film is prepared by using a low-cost natural template method. The e-skin has good performance, making it suitable for detecting small pressures and joint movements as well as high-quality electromyogram and electrocardiogram signals. The e-skin can monitor a variety of human motions and electrophysiological signals, positioning it as a promising tool in the areas of motion detection and health monitoring.
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Food Chemistry-X
·
2024
·
IF 6.5
Binchen Wang,Shaohua Dou,Shang Wang,Yi Wang,Sufang Zhang,Xinping Lin,Yingxi Chen,Chaofan Ji,Yiwei Dai,Liang Dong
Unsaturated aliphatic aldehyde oxidation plays a significant role in the deep oxidation of fatty acids to produce volatile chemicals. Exposing the oxidation process of unsaturated aliphatic aldehydes is crucial to completely comprehend how food flavor forms. In this study, thermal desorption cryo-trapping in conjunction with gas chromatography-mass spectrometry was used to examine the volatile profile of (E)-4-decenal during heating, and 32 volatile compounds in all were detected and identified. Meanwhile, density functional theory (DFT) calculations were used, and 43 reactions were obtained in the 24 pathways, which were summarized into the peroxide reaction mechanism (ROOH), the peroxyl radical reaction mechanism (ROO·) and the alkoxy radical reaction mechanism (RO·). Moreover, the priority of these three oxidative mechanisms was the RO· mechanism > ROOH mechanism > ROO· mechanism. Furthermore, the DFT results and experimental results agreed well, and the oxidative mechanism of (E)-4-decenal was finally illuminated.
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OPTICS AND LASERS IN ENGINEERING
·
2024
·
IF 3.5
Kai Li,Junyang Fang,Mingzhen Li,Long Sun,Chao Wang,Fan Du,Xiaoying Wang
Loofah-like nanostructures have been applied in many fields because of their high specific surface area, high porosity, and low density. Developing additive manufacturing methods for loofah-like nanostructures remains a challenge. This paper proposed a novel E-Jet nanoprinting method with real-time laser zone irradiation, for one-step fabricating of loofah-like ZnO nanostructures. The combination of laser irradiation and electrohydrodynamic effect had been proved in detail by adding laser irradiation to the traditional E-Jet printing process. Printable ZnO inks were prepared. The numerical model of the jetting under the combination of flow field and electric field; and the model of the interaction between laser and printing structure were established respectively. The laser beam irradiated the printing structure in real-time to rapidly absorb energy, resulting in thermal expansion and thermal decomposition. The shock wave generated by laser irradiation induced the physical fragmentation and redistribution of particles in the printed structure. Printing at different laser powers was investigated; and the loofah-like ZnO nanostructures, down to the scale of ∼90 nm, have been directly printed without post-processing. The characteristic morphology and hydrophilic characteristics of the printed structure were studied. This study provided a new way for green and efficient additive fabrication of loofah-like nanostructures, which was of significance for the development of nanofabrication and nanodevices.
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CARBOHYDRATE RESEARCH
·
2024
·
IF 2.4
Lin Wang,Yu Pang,Zhongwen Su,Meihua Xin,Mingchun Li,Yangfan Mao
N -(sodium 2-hydroxypropylsulfonate) chitosan (HSCS), N -sulfonate chitosan (SCS) and N -isonicotinic sulfonate chitosan (ISCS) were prepared. The structures of the prepared chitosan derivatives were characterized by nuclear magnetic resonance ( 1 H NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, ultraviolet–visible (UV–vis) spectroscopy and elemental analysis (EA). Antibacterial and antibiofilm activities of these chitosan derivatives were evaluated in vitro . The minimum inhibitory concentration (MIC) of HSCS and SCS against Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ) were 0.625 mg/mL and 0.156 mg/mL, respectively. ISCS exhibited MIC values of 0.313 mg/mL and 0.078 mg/mL against E. coli and S. aureus , respectively. ISCS demonstrated superior antibacterial and antibiofilm properties compared to SCS and HSCS. These findings suggest that the incorporation of a pyridine structure into sulfonate chitosan enhances its antibacterial and antibiofilm activities, and the prepared ISCS has a promising application prospect for controlling the reproduction of microorganisms in the field of food packaging.
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Biology-Basel
·
2025
·Vol. 14
·期 3
·226
·
IF 3.5
Zonghan Jiang,Leisheng Sun,Yuanyuan Li,Haoyu Li,Yu Fu,Jiyun Li,Zhiliang Sun
Simple SummaryEscherichia coliis a ubiquitous pathogen, with certain strains causing severe diarrhea and intestinal illnesses, which pose significant health risks to both children and animals. As antimicrobial resistance continues to rise, traditional antibiotics are increasingly ineffective, highlighting the urgent need for novel therapeutic strategies. In this study, we investigated the antimicrobial peptide D-CONGA-Q7, aiming to evaluate its efficacy and underlying mechanism against drug-resistantE. colistrains. Our results demonstrate that D-CONGA-Q7 effectively disrupts bacterial cell membranes, leading to bacterial death, and exhibits comparable activity against polymyxin- and meropenem-resistant strains. In vivo experiments revealed that D-CONGA-Q7 significantly alleviated intestinal inflammation, reduced inflammatory cytokine levels, and promoted the repair of damaged intestinal tissues. Furthermore, D-CONGA-Q7 displayed good stability. These findings suggest that D-CONGA-Q7 not only represents a promising new approach to combat drug-resistant bacterial infections but also holds potential for clinical application.Escherichia coli(E. coli) is a zoonotic bacterium widespread in the environment, highly transmissible, and responsible for significant economic losses and millions of cases of illness annually. The rise of multidrug-resistant (MDR) strains has rendered last-line antibiotics such as polymyxin and meropenem ineffective, making the development of new antibiotics urgent. Although D-CONGA-Q7 has broad-spectrum bactericidal activity, its underlying mechanism remains poorly understood. In this study, we used in vitro and in vivo experiments to demonstrate that D-CONGA-Q7 effectively kills both antibiotic-sensitive and multidrug-resistant strains ofE. coli. D-CONGA-Q7 disrupts the cell membranes of Gram-negative bacteria, and the treatment ofE. colistrainLN175with D-CONGA-Q7 resulted in a significant up-regulation of theMlacgene, suggesting that D-CONGA-Q7 may interact with phospholipids in the cell membrane. Furthermore, in treatingK88-induced bacterial enteritis in the small intestine, D-CONGA-Q7 significantly reduced intestinal inflammation. In conclusion, this study provides a novel approach to combat drug-resistantE. coli.
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