npj Biofilms and Microbiomes
·
2023
·Vol. 9
·期 1
·1-14
·
IF 9.2
Hu Jie,Wu Yifan,Kang Luyuan,Liu Yisi,Ye Hao,Wang Ran,Zhao Jinbiao,Zhang Guolong,Li Xilong,Wang Junjun,Han Dandan
Elimination of specific enteropathogenic microorganisms is critical to gut health. However, the complexity of the gut community makes it challenging to target specific bacterial organisms. Accumulating evidence suggests that various foods can change the abundance of intestinal bacteria by modulating prophage induction. By using pathogenic Escherichia coli ( E. coli ) ATCC 25922 as a model in this research, we explored the potential of dietary modulation of prophage induction and subsequent bacterial survival. Among a panel of sugars tested in vitro, D -xylose was shown to efficiently induce prophages in E. coli ATCC 25922, which depends, in part, upon the production of D -lactic acid. In an enteric mouse model, prophage induction was found to be further enhanced in response to propionic acid. Dietary D -xylose increased the proportion of Clostridia which converted D -lactic acid to propionic acid. Intestinal propionic acid levels were diminished, following either oral gavage with the dehydrogenase gene ( ldhA )-deficient E. coli ATCC 25922 or depletion of intestinal Clostridia by administration of streptomycin. D -Xylose metabolism and exposure to propionic acid triggered E. coli ATCC 25922 SOS response that promoted prophage induction. E. coli ATCC 25922 mutant of RecA, a key component of SOS system, exhibited decreased phage production. These findings suggest the potential of using dietary components that can induce prophages as antimicrobial alternatives for disease control and prevention by targeted elimination of harmful gut bacteria.
研究领域:
微生物学
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胃肠病学
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营养学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Yibin Yang,Di Gao,Yingqing Ou,Yang Yang,Peng Xiao,Yunhuai Zhang
Currently, developing highly active and low-cost electrocatalytic materials for oxygen evolution reaction (OER) is an enormously grand challenge. Herein, we developed a novel and highly active Mn doped Co 2 Fe layer double hydroxide (LDH) electrocatalyst for OER. We discovered that these electrocatalytic materials can be directly grown on carbon papers to construct high-specific-surface-area electrode, which shows the lowest overpotential of 266 mV at 10 mA cm −2 . Furthermore, after introducing Mn element, DFT + U calculation found that the ∗OOH of Fe-site on Co 2 Fe 0.67 Mn 0.33 LDH could draw more electrons than Co 2 Fe LDH due to the electronegativity differences between Fe-site on Co 2 Fe 0.67 Mn 0.33 LDH and Fe-site on Co 2 Fe LDH, which is reason that the energy level of Fe 3d (e g ) was obviously downshifted by d-d repulsion of Mn 3d and Fe 3d in the neighboring sites of Co 2 Fe 0.67 Mn 0.33 LDH after doped Mn element, which leads to reduce charge-transfer energy from O 2p to Fe 3d (e g ) to promote oxygen evolution processes for OER. Meanwhile, the band gap is also decreased after doped Mn element in Co 2 Fe LDH due to the downshifted e g orbital energy of Fe 3d. This study gives a general avenue to design and developing efficiently active LDH electrocatalysts for OER in the future.
研究领域:
材料科学
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电化学
·
催化
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能源材料
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产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2016
·Vol. 163
·期 7
·B373
·
IF 3.014
Qinghong Wang,Xia Lin,Juanjuan Xu,Chunzhi Xuan,Shu Zhu,Yingzi Fu
A new biosensor specified for D-amino acids (DAAs) based on the electrochemiluminescence (ECL) of luminol was proposed by coupling D-amino acid oxidase (DAAO) to in situ generate coreactant with functionalized Multi-walled carbon nanotubes (F-MWCNTs) and Au-Pt alloy nanoparticles as catalysts for the ECL reaction. The stepwise fabrication process of the biosensor was characterized via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). Furthermore, the Au–Pt nanostructures with different molar ratios between Au and Pt precursors were investigated by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) and ECL technique, and the optimum Au/Pt ratio for ECL measurements was 1:1 with an optimized electrodeposition time at 400 s. The proposed biosensor showed excellent performance in the stereoselective recognition of D-alanine with a low detection limit of 1.67 × 10−9 M. Hence, this paper would provide a new platform on the specific detection of D-alanine with high sensitivity, good selectivity and acceptable stability.
研究领域:
生物化学
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分析化学
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纳米技术
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DOI
高影响因子
Food Bioscience
·
2021
·
IF 4.24
Jiao Yuan,Yuvaraj Ravikumar,Guoyan Zhang,Junhua Yun,Yufei Zhang,Hossain M. Zabed,Xianghui Qi
l -arabinose isomerases (L-AIS) are enzymes that mediate the conversion of l -arabinose into l -ribulose and D-galactose into D-tagatose. The potential of L-AI from Lactobacillus parabuchneri CICC 6004 (LPAI) in D-galactose biotransformation using E. coli whole-cells was studied. The parameters investigated in this study were 1) the optimum pH, temperature, and cofactor specificity for maximum enzyme activity ; 2) the D-tagatose biosynthesis from D-galactose using whole-cells containing LPAI. The results showed that with D-galactose, the purified LPAI showed the highest activity, 15.52 U/mg at pH 6.7, 45 °C, and necessitates 3 mM Ca 2+ as its cofactor. The K m , V max and K cat /K m values of LPAI for D-galactose were 5.4 mM, 35.5 U/mg and 2.8 mM −1 min −1 , respectively, while the respective values for l -arabinose were found to be 4.3 mM, 63.1 U/mg and 5.9 mM −1 min −1 .The applicability of LPAI for D-tagatose synthesis was shown by using whole-cell biocatalyst approach. Under the optimum conditions, during one-stage biotransformation of D-galactose by E. coli whole cells, 39.0 g/L of D-tagatose was produced from 140 g/L of D-galactose after 50 h, which corresponded to the yield and productivity of 0.28 g/g and 0.78 g/L/h, respectively. Further addition of new cells into the reaction mixture in the second stage produced 54.0 g/L of D-tagatose after 100 h. The D-tagatose total yield and productivity were 0.39 g/g and 0.54 g/L/h, respectively. The results attained in this study showed LPAI as a potential candidate for the industrial production of D-tagatose.
研究领域:
生物化学
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生物技术
·
酶学
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微生物学
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DOI
高影响因子
BIOPROCESS AND BIOSYSTEMS ENGINEERING
·
2025
·
IF 3.6
Jin Li-Qun,Liu Meng-Dan,Guan Zi-Yu,Li Yi-Xin,Xue Ya-Ping,Liu Zhi-Qiang,Zheng Yu-Guo
DAAO is applied as a potential catalyst in the biosynthesis of L-PPT. However, its low solubility expression constrains its broader industrial application. Herein, a novel DAAO derived from Cladophialophora carrionii ( Cc DAAO) was identified, which demonstrated superior catalytic performance toward D-Ala (specific activity: 106.38 ± 1.21 U/mg, K m : 1.56 ± 0.06 mM), along with remarkable thermostability and broad substrate spectrum. Under optimal culture conditions, the soluble expression level of Cc DAAO was enhanced through a co-expression strategy with molecular chaperones, and the enzyme activity increased by 36.3% compared with the initial level. Subsequently, Cc DAAO was constructed as a fusion protein (CGD) with catalase from Geobacillus sp. CHB1 ( Gb CAT) and applied in a D-amino acid aminotransferase (DAAT)-mediated cascade system. In a 2 L reaction system, this cascade system achieved complete conversion (> 99%) of 1 M D,L-PPT within 8 h, exhibiting a yield of 11.26 g/L/h for PPO, which represents a significant improvement over existing reports. This study presents a promising practical approach for the industrial production of optically pure L-PPT.
研究领域:
生物催化
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酶工程
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药物合成
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工业微生物
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蛋白质工程
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产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Wenhao Xia,Shimeng Liu,Lihui Huang,Hao Wu,Tao Bai,Shanshan Wang,Fei Hao,Xiao Wang,Wen Wang
d -tagatose, a rare sugar with broad applications in the food and pharmaceutical industries, can be synthesized from d -fructose by epimerases, an approach with significant biosynthesis potential. However, so far there has been only one attempt to engineer tagatose 4‑epimerase through random mutagenesis. The lack of exploration has severely restricted the application of epimerases in the industrial production of d -tagatose. The previous research primarily focused on enhancing the catalytic activity of epimerases through random mutagenesis, with limited understanding of how substrate-adjacent residues affect enzyme efficiency, which was hence the subject of this study. First, using a semi-rational design approach, after three rounds of mutagenesis and screening, the mutant (S125D/S268A/Q124E) of D-tagaturonate epimerase (UxaE) from Thermotoga neapolitana was obtained, which increased d -tagatose production efficiency by 10.8-fold compared to the wild type, with a specific activity of 1505.6 U/g, representing the highest specific activity reported for a UxaE mutant to date. Molecular dynamics simulations showed that the substitution of Ser to Asp-125 enhanced substrate-enzyme interactions, while the substitution of Glu to Gln-124 reinforced the hydrogen bond network around the catalytic residue Glu-128, further reshaping the substrate-binding pocket and enhancing catalytic activity. This study for the first time explored the enhancement of the C4 epimerization function of epimerases by reshaping their substrate-binding pockets, thereby providing a feasible route for the industrial biosynthesis of d -tagatose.
研究领域:
生物化学
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生物技术
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酶工程
·
分子生物学
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产品关联
DOI
高影响因子
LUMINESCENCE
·
2019
·Vol. 34
·期 7
·767-773
·
IF 1.691
Chunlei Ma,Wensheng Ren,Jianke Tang,Xiaoli Wang,Dongxin Ji,Rongqian Meng,Cuihong Zhang,Qi Wang
Taking advantage of the compelling properties of d -penicillamine ( d -PA) combined with copper, a method for the sensitive and selective determination of d -PA was established using copper nanocluster (Cu NC)-based fluorescence enhancement. d -PA molecules containing a thiol compound showed a strong tendency to combine with the surface of Cu NCs, causing the re-dispersion of nanoclusters and therefore fluorescence intensity was enhanced. Fluorescence enhancement efficiency of Cu NCs induced by d -PA was linear, with the d -PA concentration varying from 0.6–30 μg ml −1 (R 2 = 0.9952) and with a detection limit of 0.54 μg ml −1 . d -PA content in human urine samples was detected with recoveries of 104.8–112.99%. Fluorescence-enhanced determination of d -PA using Cu NCs was established for the first time and this rapid, easy and sensitive method should attract much attention for this application.
研究领域:
分析化学
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纳米技术
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生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Lin-Fu Xie,Wan-Hong Huang,Jian-Ping Chen,Hai-Lin Chen,Cheng Hou,Qing-Ling Ni,Ting-Hong Huang,Liu-Cheng Gui,Xiu-Jian Wang
Photocatalytic selective oxidation plays an important role in developing green chemistry. However, it is challenging to design an efficient photocatalyst for controlling the selectivity of photocatalytic oxidation reaction and exploring its detailed mechanism. Here, we synthesized three conjugated microporous polymers (CMPs) with D-A structures, named M−SATE−CMPs (M Zn, Cu and Co), with different d-band centers based on different metal centers, resulting in the discrepancy in adsorption and activation capacities for the reactants, which produces the selectivity of β-keto esters being catalyzed into α-hydroperoxide β-keto esters (ROOH) or to α-hydroxyl β-keto esters (ROH). Density functional theory (DFT) calculations also demonstrate that the adsorption and activation capacities of the metal active centers in M−SATE−CMPs (M Zn, Cu and Co) for ROOH are the key factors to influence the photocatalytic selective oxidation of β-keto ester. This study provides a promising strategy for designing a metallaphotoredox catalyst whose photocatalytic selectivity depends on the d-band center of metal site in the catalyst.
研究领域:
化学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
Foods
·
2024
·Vol. 13
·期 11
·1727
·
IF 4.7
Chengyu Lu,Ziwei Chen,Yuvaraj Ravikumar,Guoyan Zhang,Xinrui Tang,Yufei Zhang,Mei Zhao,Wenjing Sun,Xianghui Qi
L-Arabinose isomerase (L-AI) has been commonly used as an efficient biocatalyst to produce D-tagatose via the isomerization of D-galactose. However, it remains a significant challenge to efficiently synthesize D-tagatose using the native (wild type) L-AI at an industrial scale. Hence, it is extremely urgent to redesign L-AI to improve its catalytic efficiency towards D-galactose, and herein a structure-based molecular modification ofLactobacillus plantarumCY6 L-AI (LpAI) was performed. Among the engineered LpAI, both F118M and F279I mutants showed an increased D-galactose isomerization activity. Particularly, the specific activity of double mutant F118M/F279I towards D-galactose was increased by 210.1% compared to that of the wild type LpAI (WT). Besides the catalytic activity, the substrate preference of F118M/F279I was also largely changed from L-arabinose to D-galactose. In the enzymatic production of D-tagatose, the yield and conversion ratio of F118M/F279I were increased by 81.2% and 79.6%, respectively, compared to that of WT. Furthermore, the D-tagatose production of whole cells expressing F118M/F279I displayed about 2-fold higher than that of WT cell. These results revealed that the designed site-directed mutagenesis is useful for improving the catalytic efficiency of LpAI towards D-galactose.
研究领域:
生物化学
·
食品科学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2019
·Vol. 103
·期 21
·8839-8851
·
IF 3.67
Liu Yang,Zhu Lingfeng,Qi Wenpeng,Yu Bo
D- p -hydroxyphenylglycine (D-HPG) functions as an intermediate and has important value in antibiotic industries. The high pollution and costs from chemical processes make biotechnological route for D-HPG highly desirable. Here, a whole-cell transformation process by D-hydantoinase(Hase) and D-carbamoylase(Case) was developed to produce D-HPG from DL-hydroxyphenylhydantoin(DL-HPH) in Escherichia coli . The artificially designed ribosome binding site with strong intensity significantly facilitated the protein expression of limiting step enzyme Case. Next, the cell wall permeability was improved by disturbing the peptidoglycan structure by overproduction of D,D-carboxypeptidases without obviously affecting cell growth, to increase the bioavailability of low soluble hydantoin substrate. By fine-tuning regulation of expression level of D,D-carboxypeptidase DacB, the final production yield of D-HPG increased to 100% with 140 mM DL-HPH substrate under the optimized transformation conditions. This is the first example to enhance bio-productivity of chemicals by cell wall engineering and creates a new vision on biotransformation of sparingly soluble substrates. Additionally, the newly demonstrated ‘hydroxyl occupancy’ phenomenon when Case reacts with hydroxyl substrates provides a referential information for the enzyme engineering in future.
研究领域:
生物技术
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微生物学
·
生物化工
·
酶工程
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DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Dongbo Wang,Xuan Zhou,Yanbo Liu,Mingyang Chen,Dandan Han,Junbo Gong
With the rise of research on functional sugar, we found that preparing crystalline powders into spherical crystals will significantly improve quality, stability, appearance, and texture. In this work, d-ribose (D-RIB) spherical crystal aggregates were prepared for the first time. And D-RIB spherical crystal aggregates with superior filterability, flowability, and tap density can be prepared in ethanol, 1-propanol, and isopropanol. Specifically, we used ethanol as an example to reveal the formation mechanism of D-RIB spherical crystal aggregates: solvent-induced crystal defects, which in turn trigger noncrystallographic branching and further spherulite growth. Finally, a comparison of the properties of the D-RIB spherical crystal aggregates with those of commercially available products is given, demonstrating the fabrication of D-RIB spherulites with better tap density and flowability by solvent-induced noncrystallographic branching. This will provide a new insight into the preparation of high-quality D-RIB crystals.
研究领域:
化学
·
材料科学
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产品关联
DOI
高影响因子
ACS Applied Electronic Materials
·
2022
·
IF 4.494
Zhang Chen,Xiaotian Sun,Zizheng Wang,Yong Zhu,Chuanxiang Cao,Jiadong Zhou,Yanfeng Gao
Porous carbon was fabricated for broadband microwave absorption application, which was obtained from facile KOH activated carbon microspheres prepared from hydrothermal d-fructose. It is found that micropores (diameter < 2 nm) in the porous carbon played an important role in broadband and high microwave absorption properties. The prepared samples can achieve a wide bandwidth (the widest is 7.9 GHz, from 10.1 to 18 GHz), high dielectric loss (−60.0 dB as the best), and low thickness sensitivity (the bandwidth maintains 70% of the maximum within a film thickness fluctuation of up to 1.02 mm). Our findings offered an invaluable insight into designing and synthesizing highly microwave-absorbing materials through the micro/nanostructure.
研究领域:
材料科学
·
电磁学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）