ELECTROANALYSIS
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2019
·Vol. 32
·期 1
·142-148
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IF 2.691
Yue Zhang,Ziyao Lv,Jie Zhou,Yan Fang,Hao Wu,Fengxue Xin,Wenming Zhang,Jiangfeng Ma,Ning Xu,Aiyong He,Weiliang Dong,Min Jiang
In this study, stable CotA laccase from Bacillus subtilis 168 was adsorbed on electrode modified with a thiol graphene-gold nanoparticle (thGP-AuNPs) nanocomposite film. The novel bacterial laccase biosensor was employed for quantitative detection of hydroquinone (HQ) and the electrochemical properties of this laccase biosensor were investigated. The results indicate that the immobilized CotA shows great oxidation activity towards HQ in the presence of oxygen and the biosensor shows linear electrocatalytic activity in the concentration range from 1.6 to 409.6 μM, with a detection limit of 0.3 μM. Further, the CotA modified electrode, when compared to fungal laccase-modified biosensors, shows better alkaline stability (retaining approximately 80 % and 70 % of response current at pH 8 and 9, respectively) and reusability (retaining ∼87 % of response current after 100 days). The development of this new kind of laccase on a biosensor will offer a novel tool for substance detection applications in hostile environments, especially for industrial pollutants.
研究领域:
生物技术
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环境科学
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分析化学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2019
·
IF 4.784
Weichuan Qiao,Hai Liu
In this study, a CotA laccase from Bacillus subtilis cjp3 was successfully immobilized onto magnetic graphene oxide (MGO) nanomaterials via covalent bonding with hydrochloride/N-hydroxysuccinimide (EDC/NHS). The morphology, structure, and properties of the MGO-laccase were then characterized by scanning-electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray-photoelectron spectroscopy (XPS), and a magnetic-property-measurement system (MPMS). The magnetic composite exhibited an extremely high binding capacity of ~145.04 mg/g and maintained maximal relative enzyme activities at 25 °C, pH 7, and a reaction time of 2 h. The pH, thermal, operational, and storage stabilities of MGO-laccase were significantly improved over those of free laccase. Moreover, MGO-laccase exhibited a higher tolerance than that of free laccase in the presence of organic solvents , inhibitors, metal ions, and salts. Furthermore, MGO-laccase showed good decolorization performance of malachite green (MG), with decolorization rates reaching 99% after 5 h of reaction at 30 °C and pH 6. In addition, the maximum saturation magnetization of MGO-laccase was 27.7 emu/g, allowing for rapid magnetic separation. Accordingly, magnetic separation allowed MGO-laccase to maintain 75% of its activity after ten consecutive decolorization cycles.
研究领域:
生物技术
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环境科学
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产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
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2017
·
IF 0
Nadia A. Samak,Yeqiang Tan,Kunyan Sui,Ting-Ting Xia,Kefeng Wang,Chen Guo,Chunzhao Liu
In this work, a novel type of functionalized magnetic graphene oxide (MGO) nano-sheets which have the ability to capture His-tagged CotA laccase was synthesized. Nα,Nα-Bis(carboxymethyl)- l -lysine hydrate (NTA-NH 2 ) was attached on MGO then chelated with Ni 2+ and Cu 2+ separately. The Cu 2+ -chelated MGO (MGO-NTA-Cu 2+ ) exhibited the highest adsorption capacity of 177 mg/g-support when compared with both MGO and Ni 2+ -chelated MGO (MGO-NTA-Ni 2+ ) which exhibited an adsorption capacity of 49.9 and 145 mg/g-support, respectively. CotA laccase immobilized on MGO-NTA-Cu 2+ nano-sheets showed the highest activity recovery when compared with that immobilized on MGO-NTA-Ni 2+ nano-sheets. The catalytic properties of MGO-NTA-Cu-CotA laccase were significantly improved in comparison with those of the free laccase. MGO-NTA-Cu-CotA laccase showed efficient decolorization for Congo Red (CR), and the decolorization rate reached 100% after 5 h reaction at 60 °C and pH 8. Furthermore, MGO-NTA-Cu-CotA laccase retained 89.4% of its initial activity after 10 consecutive cycles. Together these results indicated that the Cu 2+ chelated MGO nano-sheets are promising support for efficient CotA laccase immobilization for environmental and industrial applications under high temperature and alkaline condition.
研究领域:
生物技术
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环境科学
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工业应用
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产品关联
DOI
Waste and Biomass Valorization
·
2022
·Vol. 14
·期 1
·127-144
·
IF 3.449
Mahmoud Tahany,Liu Chunzhao,Samak Nadia A.
CotA laccase was successfully expressed from Pichia pastoris . Magnetic reduced graphene oxide (MRGO) nanocomposite was synthesized and functionalized with iminodiacetic acid (IDA-NH 2 ), and then chelated with Cu 2+ for effective immobilization with His-tagged CotA laccase. The Cu 2+ -chelated MRGO (MRGO-IDA-Cu 2+ ) showed 175 mg/g-support adsorption capacity. The immobilization of CotA laccase with MRGO-IDA-Cu 2+ nano-hybrid composite was confirmed by Raman spectroscopy, Thermal Gravimetric Analysis, and X-ray diffraction. The use of nano-hybrid MRGO-IDA-Cu 2+ composite to improve heavy oil recovery was investigated. The findings revealed that the interfacial tension between oil and water was reduced to ~ 90% of its original value, and the wettability was changed from the oil-wet state [θ = ∼ 115.2 − 124.5°] to the water-wet state [θ = ∼ 8.9 − 30.1°]. The increase of immobilized CotA laccase concentration and the ratio of nano-hybrid MRGO-IDA-Cu 2+ composite decreases the value of interfacial tension (IFT) and contact angle (CA). The core-flooding studies revealed that the oil recovery process of 0.3 wt% nano-hybrid MRGO-IDA-Cu 2+ composite was enhanced by 82.8%. Graphical Abstract
研究领域:
生物化学
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环境科学
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材料科学
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DOI
高影响因子
Frontiers in Microbiology
·
2025
·
IF 4.5
Xiaomin Zhu,Youren Duan,Jianqi Lu,Wei Xia,Yujia Peng,Jiawei Liu,Weiliang Dong,Min Jiang
Polyurethane (PU), a segmented block copolymer with chemically resistant urethane linkages and tunable architecture, presents persistent biological recycling challenges. This study presents a Bacterial Laccase-Mediated System (BLMS) derived from Bacillus subtilis for efficient degradation of polyester- and polyether-PU. Utilizing the laccase CotA and mediator 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), the BLMS demonstrated effective de polymerization of both commercial and self-synthesized PU foams, including polyester- and polyether-types. The weight loss of the self-synthesized polyester-foam and the commercial polyether-foam reached up to 21.24 ± 1.20% and 3.81 ± 0.36%, respectively. Subsequently, we detected oxygenated products such as ketones, alcohols, aldehydes, acids, esters, ethers, and 2,4– toluenediamine (2,4-TDA) indicating that bacterial laccase CotA exhibited redox catalytic activity toward PU. Moreover, an interesting phenomenon was observed during the degradation process that the solution turned purple. We predicted that this attribute to the enzymatic oxidation of ABTS to the radical cation ABTS·+, which subsequently reacts with 2,4-TDA to form the purple product. This study finds a plastic degrading enzyme capable of hydrolyzing urethane bonds in PU, offering a promising contribution to the development of a bio-based circular economy for PU biodegradation and recycling.
研究领域:
生物降解
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酶催化
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高分子科学
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生物工程
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环境生物技术
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产品关联
DOI
PubMed
高影响因子
Frontiers in Bioengineering and Biotechnology
·
2018
·
IF 0
Liang Yuanmei,Hou Juan,Liu Ying,Luo Yifan,Tang Jie,Cheng Jay J.,Daroch Maurycy
Cyanobacteria are prokaryotic phototrophs capable of achieving high cellular densities with minimal inputs. These prokaryotic organisms can grow using sunlight as energy source and carbon dioxide as carbon source what makes them promising candidates as microbial cell factories for the production of numerous compounds such as chemicals, fuels, or biocatalysts. In this study, we have successfully designed and constructed using synthetic biology approach two recombinant strains of Synechococcus elongatus PCC7942 for heterologous expression of the industrially relevant Bacillus subtilis CotA laccase. One of the strains (PCC7942-NSI-CotA) was constructed through integration of the laccase gene into neutral site I of the cyanobacterial genome whilst the other (PCC7942-NSII-CotA) targeted neutral site II of the genome. Of the two strains the one with CotA laccase integrated in neutral site II (PCC7942-NSII-CotA) was superior in terms of growth rate and enzymatic activity toward typical laccase substrates: ABTS [2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonate)] and syringaldazine. That may suggest that two of the traditionally used neutral sites of S. elongatus PCC7942 are not equally suitable for the expression of certain transgenes. The PCC7942-NSII-CotA produced protein was capable of decolourising three classes of dyes namely: anthraquinonic-, azo-, and indigoid-type over 7 days of incubation making the strain a potentially useful microbial cell factory for the production of broad-spectrum biodegradation agent. Interestingly, presence of additional synthetic redox mediator ABTS had no effect on the degradation of these dyes.
研究领域:
合成生物学
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生物技术
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环境工程
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微生物学
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产品关联
DOI
PubMed
JOURNAL OF HAZARDOUS MATERIALS
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2021
·
IF 10.588
Yuqing Qin,Aroosha Faheem,Yonggang Hu
The excess residues of fluoride ions cause serious human health problems, making their detection highly valuable. In this work, a whole-cell-based biosensor was presented for the detection of fluoride ions, which can inhibit the color reaction of 3,3′,5,5′,-tetramethylbenzidine (TMB) catalyzed by the CotA-laccase of spore surface. This reaction for the detection of fluoride ions could be read out through UV–vis spectrophotometer, smartphone, or standard colorimetric card within 10 min. Under optimum conditions, a linear range of 1–600 μmol L –1 with a detection limit of 0.12 μmol L –1 (3σ/k) was achieved for fluoride ions detection by using UV–vis spectrophotometer. The biosensor coupling with smartphone had a good linear response to fluoride ions concentration in the range of 5–600 μmol L –1 with LOD of 0.90 μmol L –1 (3σ/k). The standard colorimetric card can be directly used for recognizing the fluoride ions level via naked-eyes. A portable kit based on a colorimetric card and smartphone was developed and has been successfully applied for fluoride ions monitoring in surface waters and groundwater. This developed method has several advantages such as rapid, outstanding selectivity and anti-interference, low-cost, ease of operation and storage, and eco-friendliness, meeting the demands of point-of-care testing of fluoride ions and disease prevention.
研究领域:
环境科学
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分析化学
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生物技术
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产品关联
DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2019
·Vol. 21
·期 9
·2286-2294
·
IF 9.405
Yuqing Qin,Fei Peng,Yonggang Hu
The oxidation of As(III) to As(V) is a critical process in the treatment of contaminated water. We found that 95% As(III) (10 mg L−1) could be rapidly oxidized to As(V) by a laccase–2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) system in 1 h. Based on this finding, we used Bacillus subtilis spores instead of laccase for As(III) oxidation with the same effect because the former had plenty of CotA–laccase on their surface. The catalytic ability of CotA protein and spores was confirmed by expressing the CotA protein and knocking out the cotA gene from wild-type spores. Both laccase– and spore–TEMPO systems displayed similar oxidation rate constants, Michaelis–Menten constants, and maximal velocities owing to the formation of the oxoammonium cation of TEMPO in the presence of dissolved oxygen. Several other laccase mediators such as 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic-acid) (ABTS), acetosyringone (AS), 1-hydroxybenzotriazole (HBT), 2-hydroxybutyl acrylate (HBA), violuric acid (VLA), 4-oxo-TEMPO, 4-amino-TEMPO, 4-methoxy-TEMPO, 4-hydroxy-TEMPO benzoate, and 4-hydroxy-TEMPO coupled with spores for As(III) oxidation were also investigated in detail. The spore–TEMPO system exhibited the highest oxidation efficiency and tolerated the addition of 10 mg L−1 Al3+, Ti4+, Cu2+, K+, Fe3+, Zn2+, Ni2+, Mg2+, Co2+, and Mn2+. Both laccase and spores recovered via ultrafiltration and centrifugation, respectively, could be reused for at least five cycles. The developed spore-based system has several advantages including eco-friendliness, ease of operation and storage, low cost, recyclability, sustainability, and without the need for enzyme purification. These findings may have promising implications for developing a new eco-friendly and cost-effective technology for the treatment of arsenic-containing water.
研究领域:
环境科学
·
生物技术
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水处理
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微生物学
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产品关联
DOI
高影响因子
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