ENVIRONMENTAL MICROBIOLOGY
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2023
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IF 5.1
Yingying Qian,Minggen Cheng,Lin Lai,Jing Zhou,Gerben J. Zylstra,Xing Huang
Overuse of the amphenicol antibiotics chloramphenicol (CHL) and thiamphenicol (TAP) poses a great threat to ecosystem safety and human health. The strain, Nocardioides sp. LMS-CY, Nocardioides sp. QY071 and Nocardioides sp. L-11A, classified as a gram-positive actinomycete, harbours a complete CHL metabolic pathway. However, the metabolic genes (clusters) involved in the entire pathway in gram-positive actinomycetes are still limited. Here, chlOR LMS , chlOR QY071 and chlOR L-11A completely from the actinomycete Nocardioides spp. were found to act on the C 1 -OH of the CHL/TAP side chain, directly converting CHL/TAP to 4-nitrobenzaldehyde (PNBD)/4-methylsulfonyl benzaldehyde (PMBD) and transforming PNBD/PMBD into 4-nitrobenzyl alcohol (PNBM)/4-methylsulfonyl phenyl methanol (PMBM). Furthermore, oxidoreductases can transform PNBM into 4-nitrobenzoate (PNBA). The oxidoreductases ChlOR LMS , ChlOR QY071 and ChlOR L-11A were all classified as cellobiose dehydrogenases from the glucose methanol choline (GMC) family. Based on the Swiss-Prot database, ChlOR QY071 exhibited a lower identity (27.12%–35.10% similarity) with the reported oxidoreductases. Enzymatic and molecular docking analyses showed that ChlOR QY071 and ChlOR L-11A from the two similar genomes were remarkably more effective in metabolizing CHL than ChlOR LMS . Overall, the detailed resistance mechanism of CHL/TAP by actinomycete strains isolated from soil and livestock manure will provide insights into the occurrence of CHL/TAP resistance genes in the environment, resistance risk and bioremediation of CHL/TAP-contaminated environments.
研究领域:
微生物学
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环境科学
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药理学
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生物化学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2011
·Vol. 16
·期 2
·449-456
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IF 2.234
Han Ruixia,Cui Lin,Ai Shiyun,Yin Huanshun,Liu Xianggang,Qiu Yanyan
A tyrosinase (Tyr) biosensor has been constructed by immobilizing tyrosinase on the surface of Mg–Al–CO 3 hydrotalcite-like compound film (HTLc) modified glassy carbon electrode (GCE) for the determination of polyphenols. The negatively charged tyrosinase was adsorbed firmly on the surface of a positively charged HTLc/GCE by electrostatic interactions and retained its activity to a great degree. The modified electrode was characterized by cyclic voltammetry and AC impedance spectra. Polyphenols were determined by a direct reduction of biocatalytically generated quinone species. The different parameters, including pH, temperature, and enzyme loading were investigated and optimized. Under the optimum conditions, Tyr/HTLc electrode gave a linear response range of 3–300, 0.888–444, and 0.066–396 μM with a detection limit (S/N = 3) of 0.1, 0.05, and 0.003 μM for catechol, caffeic acid, and quercetin, respectively. In addition, the repeatability and stability of the enzyme electrode were estimated. Total polyphenol contents of real samples were also determined to study the potential applicability of the Tyr/HTLc/GCE biosensor.
研究领域:
生物传感器
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酶学分析
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电化学检测
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DOI
高影响因子
MICROCHIMICA ACTA
·
2016
·Vol. 183
·期 8
·2403-2409
·
IF 4.831
Ye Cui,Zhong Xia,Wang Min-Qiang,Chai Yaqin,Yuan Ruo
A glassy carbon electrode (GCE) was modified with a nanocomposite consisting of tetraoctylammonium bromide (TOAB), C 60 fullerene, and palladium nanorods (PdNRs). The PdNRs were hydrothermally prepared and had a typical width of 20 ± 2 nm. The nanocomposite forms stable films on the GCE and exhibits a reversible redox pair for the C 60 /C 60
− system while rendering the surface to be positively charged. The modified GCE was applied to fabricate an electrochemical biosensor for detecting acetylcholinesterase (AChE) by measurement of the amount of thiocholine formed from acetylthiocholine, best at a working voltage of −0.19 V (vs. SCE). The detection scheme is based on (a) measurement of the activity of ethyl paraoxon-inhibited AChE, and (b) measurement of AChE activity after reactivation with pralidoxime (2-PAM). Compared to the conventional methods using acetylthiocholine as a substrate, the dual method presented here provides data on the AChE activity after inhibition and subsequent reactivation, thereby yielding credible data on reactivated enzyme activity. The linear analytical range for AChE activity extends from 2.5 U L −1 to 250 kU·L −1 , and the detection limit is 0.83 U L −1 .
Cyclovoltammetric acetylcholinesterase (AChE) activity assay is constructed based on the palladium nanorods composited with functionalized C 60 fullerene (PdNR/C 60 + TOAB), which aims to measure the signal change between ethyl paraoxon-inhibited and subsequent pralidoxime (2-PAM)-reactivated AChE activity.
研究领域:
生物传感
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酶学分析
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纳米材料修饰电极
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电化学检测
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毒理学
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DOI
高影响因子
MICROCHIMICA ACTA
·
2025
·Vol. 192
·期 9
·1-10
·
IF 5.3
Wang Feifei,Wang Xinling,Wang Yu,Zhang Yin,Liu Tianxiang,Sun Jian
A novel and facile fluorescence turn-on assay for detecting α-glucosidase (α-Glu) activity and screening inhibitors is reported. This assay exploits α-Glu-catalyzed hydrolysis of L-ascorbic acid-2-O-α-D-glucopyranosyl (AA2G) to release ascorbic acid (AA), triggering an in situ fluorogenic reaction with N-methylethylenediamine (N-MEDA) that generates non-conjugated polymer dots (NCPDs). These NCPDs emit blue fluorescence at 425 nm upon excitation at 350 nm, and the fluorescence intensity increases proportionally with the concentration of α-Glu, enabling quantitative detection of enzymatic activity. The fluorescent assay demonstrates a linear response ranging from 0.01 to 10 U/mL and achieves a low detection limit of 0.0034 U/mL, surpassing most existing methods in sensitivity and width of linear range. In addition, the proposed method has been successfully applied to screen α-Glu inhibitors (AGIs) and determine α-Glu activity in real samples, yielding satisfying results. This work introduces a robust analytical framework and promising approach for clinical diagnosis and anti-diabetic drug discovery. Graphical
研究领域:
生物化学
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分子生物学
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药物发现
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临床诊断
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酶学分析
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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