FEBS Open Bio
·
2020
·Vol. 10
·期 12
·2733-2739
·
IF 2.231
Sai-sai Ding,Jin-peng Zhu,Yang Wang,Bin Wu,Zongpei Zhao
In the paper industry, chlorine is often used to treat the pulp for bleaching. After pulping, a large amount of xylan is present in the fiber. Xylanase can be used to degrade xylan in an eco-friendly process called biobleaching, which can help minimize the usage of chlorine in the delignification process. However, a bottleneck in the adoption of biobleaching is the cost of xylanase and the requirement that xylanase be active and stable at extreme conditions. Here, we investigated whether using sodium alginate beads to immobilize an extracellular xylanase from Bacillus subtilis (Lucky9) can reduce the potential cost of enzyme usage. The optimal pH and the activity of the immobilized enzyme were increased at optimal temperature compared with the free enzyme. In addition, immobilized xylanase was shown to be more stable than free xylanase. The results of this study suggest that the immobilized xylanase has potential applications in the biobleaching industry.
研究领域:
生物技术
·
酶工程
·
制浆造纸工业
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DOI
PubMed
高影响因子
Journal of Analytical Science and Technology
·
2021
·Vol. 12
·期 1
·1-12
·
IF 2.769
Chen Kangni,Li Yanbo,Shang Jinyan,Li Heping
Biothiols play important roles in various physiological and biological processes, which closely related to many diseases. Hydrazine is widely used in the chemical industry, but it is harmful to humans and animals. Therefore, it is very important to develop a fluorescent probe that can simultaneously detect biological thiols and hydrazine. In this work, a new fluorescent probe (2E,4Z)-2-(benzo[d]thiazol-2-yl)-5-chloro-5-(7-(diethylamino)-2-oxo-2H-chromen-3-yl)penta-2,4-dienenitrile (BCD) was synthesized by integrating coumarin and benzothiazole acetonitrile. Featured with four binding sites and different bonding mechanism between probe with biothiols and hydrazine, this probe exhibited fluorescent turn-on for distinguishing Cys, Hcy, GSH and hydrazine with 760-, 8-, 6- and 637-fold fluorescent intensity increase at 502, 479, 476 and 458 nm, respectively, through different excitation wavelengths. Research on the effect of pH on the fluorescent performance of BCD shows that the probe exhibits superior stability in a weakly alkaline to weakly acidic environment, which will facilitate the detection of biological thiols or hydrazine hydrate by BCD. Selectivity studies have shown that the probe has high specificity to biological thiols and hydrazine, which is of great significance to the application of BCD.
研究领域:
分析化学
·
生物化学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 41
·期 14
·6646-6652
·
IF 3.269
Ke Zhang,Lingling Luo,Wenjie Li,Honglin Zhang,Yi Zhang,Jiupeng Zhao,Yao Li
The preparation of polystyrene (PS) beads loaded with platinum octaethylporphyrin (PtOEP) via a swelling method has been well incorporated into dissolved oxygen (DO) sensing detection. The experimental results showed that the highest value of I0/I100 was 7.26 and the loading ratio of PtOEP was 51.33%; the luminescent intensity declined by only 2.23% under UV light for 1 hour. The response and recovery times were 16 s and 180 s, respectively. The peak position and intensity of the emission spectrum in buffer solutions with different pH values did not change. This indicates that this oxygen sensor has excellent sensitivity, light stability, reversibility, and pH resistance. Moreover, on this basis, we incorporated another oxygen insensitive dye, coumarin 6 (C6), to prepare a ratiometric oxygen sensor, which showed high sensitivity towards O2 with superior quenching efficiency. Finally, this oxygen sensor was used to monitor the content of DO in fish tank, tap water, and the Songhua River. All the measured results were well within the reference range.
研究领域:
生物化学
·
材料科学
·
环境监测
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DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2017
·Vol. 17
·期 1
·370-376
·
IF 1.483
Xia Guo-Hua,Liu Wei,Jiang Xiao-Ping,Wang Xiang-Yu,Zhang Ye-Wang,Guo Jianyong
Magnetic Fe3O4 nanoparticles were prepared through hydrothermal method and coated with silica on the surface to obtain Fe3O4@SiO2 core–shell nanoparticles. After modification with different functional groups including aldehyde,
amine and diimide, the nanoparticles were used as carrier for covalent immobilization of lipase. The nanoparticles with aldehyde groups showed highest immobilization yield (52.8%) and efficiency (86.5%). And the immobilization conditions including pH, temperature and the concentration of enzyme
were optimized. After immobilization, the K
m of lipase was altered from 2.3 to 3.2 mM. The thermal stability and pH stability were enhanced by immobilization at the investigated conditions: pH 5.0–8.0 and temperature 30–70 °C. After 10 batches conversion of
4-Nitrophenyl palmitate into p-Nitrophenol, the immobilized lipase retained over 75% of the original activity. Compared with the commercial lipase Novozym435, the immobilized lipase showed better stability and higher catalytic efficiency. These results demonstrate that the immobilized lipase
on the modified Fe3O4@SiO2 magnetic nanoparticles has enhanced stability and reusability, which make lipase of potential interest in a number of industrial applications.
研究领域:
生物化学
·
纳米材料科学
·
酶工程
✓ 已验证
DOI
PubMed
高影响因子
FOOD HYDROCOLLOIDS
·
2020
·
IF 7.053
Xuan Zhang,Hongshan Liang,Jing Li,Xianling Wei,Bin Li
In the present work, sodium carboxymethyl cellulose (CMCNa) was utilized to improve the emulsifying property of gliadin colloid particles (GCPs). We demonstrated the use of gliadin/CMCNa complex particles (GCCPs) as stabilizer to stabilize oil-in-water emulsions in a wide pH range (3.0–9.0) at a very low protein concentration (0.1%, w/v) which could be kept at room temperature for three months without oil-leakage. The effect of gliadin/CMCNa ratio, pH and ionic strength on emulsifying property of gliadin-based particles was investigated, and the stability of Pickering emulsions fabricated by GCCPs at a series of pH (3.0–9.0) to a four-week-long storage was evaluated. The optimized emulsifying property of particles was achieved at a gliadin/CMCNa ratio of 2:1, and Pickering emulsions stabilized by GCCPs at this ratio had a high tolerance for aqueous phase pH variation. Furthermore, the possible mechanisms were discussed by investigating the effect of gliadin/CMCNa ratio on wettability and adsorption behavior of particles at pH 4.0 and pH 7.0. Moderate wettability was achieved at the gliadin/CMCNa ratio of 1:1 at pH 4.0 and 2:1 at pH 7.0. The surface loading percentage of protein of Pickering emulsions increased from 70.28 ± 1.97% to 82.02 ± 6.20% and the surface protein loading (τ) decreased from 267.53 ± 5.31 mg/m 2 to 149.17 ± 4.45 mg/m 2 with the increase of CMCNa concentration, indicating the adsorption and emulsifying activity of particles could be enhanced by CMCNa addition.
研究领域:
食品科学
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界面化学
·
材料科学
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DOI
高影响因子
Sustainability
·
2022
·Vol. 14
·期 21
·14097
·
IF 3.889
Jiangyi Yan,Lihong Nie,Guiliang Li,Wenxin Wu,Ming Gao,Yuanlu Zhu,Weixing Wu,Beifu Wang
In this paper, we report for the first time the successful formation of a covalent cross-linking structure between polyacrylic acid and polyamide 66 in an electrospun nanofiber membrane by the facilitated amidation reaction using N-Hydroxy-succinimide (NHS) and N-(3-Dimethylaminopropyl)-N’-ethyl-carbodiimide hydrochloride (EDC). The structure and properties of the fiber membrane are characterized using scanning electron microscopy, wide field X-ray diffraction and differential scanning calorimetry. The results show that the presence of the cross-linked structure not only affects the construction of the nanofiber network framework but also influences the pore size distribution and size of the fiber membrane surface, which in turn affects its retention of contaminants and water absorption performance. After modification, the cross-linked membranes exhibited a significant retention performance of up to 77% for methyl tert-butyl ether (MTBE) with a reduced pure water flux. Furthermore, after crosslinking, the fiber membrane has been strongly enhanced with more stable pH response behavior.
研究领域:
材料科学
·
化学工程
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DOI
高影响因子
Foods
·
2021
·Vol. 10
·期 11
·2819
·
IF 4.35
Huibing Chi,Meirong Chen,Linshu Jiao,Zhaoxin Lu,Xiaomei Bie,Haizhen Zhao,Fengxia Lu
L-asparaginase (E.C.3.5.1.1) is a well-known agent that prevents the formation of acrylamide both in the food industry and against childhood acute lymphoblastic leukemia in clinical settings. The disadvantages of L-asparaginase, which restrict its industrial application, include its narrow range of pH stability and low thermostability. In this study, a novel L-asparaginase fromMycobacterium gordonae(GmASNase) was cloned and expressed inEscherichia coliBL21 (DE3). GmASNase was found to be a tetramer with a monomeric size of 32 kDa, sharing only 32% structural identity withHelicobacter pyloriL-asparaginases in the Protein Data Bank database. The purified GmASNase had the highest specific activity of 486.65 IU mg−1at pH 9.0 and 50 °C. In addition, GmASNase possessed superior properties in terms of stability at a wide pH range of 5.0–11.0 and activity at temperatures below 40 °C. Moreover, GmASNase displayed high substrate specificity towards L-asparagine with Km, kcat, and kcat/Km values of 6.025 mM, 11,864.71 min−1and 1969.25 mM−1min−1, respectively. To evaluate its ability to mitigate acrylamide, GmASNase was used to treat potato chips prior to frying, where the acrylamide content decreased by 65.09% compared with the untreated control. These results suggest that GmASNase is a potential candidate for applications in the food industry.Keywords:L-asparaginase;acrylamide;Mycobacterium gordonae;thermal stability
研究领域:
食品科学
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酶学
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生物技术
·
生物化学
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DOI
PubMed
高影响因子
CRYOLETTERS
·
2023
·Vol. 44
·期 5
·280-290
·
IF 1
Wu Jiawei,Liu Yeyu,Zhang Jinping,Wang Xiaohui
BACKGROUND: Chitin is the second largest carbon source on the earth, and chitosan oligosaccharides produced by its degradation have good application prospects in medicine, cosmetics, and agricultural production. OBJECTIVE: The discovery of a chitinase with high efficiency,
high stability and clear degradation mechanism is of great help to promote the research of chitin derivatives and the development of the industrial chain. MATERIALS AND METHODS: In this experiment, a lowtemperature chitinase-producing strain Photobacterium sp. LG-29 was isolated
from deep-sea mud in the Bohai Sea, and studied by means of molecular biology, biochemistry and bioinformatics. RESULTS: Purification of chitinase yielded an enzyme solution with a concentration of 0.918 mg/mL and a specific activity of 21.036 U/mg. The optimum action temperature is
35°C, and it is still active at 4°C, showing low-temperature enzymatic activity, and also has certain thermal stability. The optimum pH is 8.0, and it maintains more than 70% of the enzyme activity at pH 11, which is very stable in an alkaline environment. Mn2+, Ca2+,
and Mg2+ are the main activators of enzymes, while Fe2+, Zn2+, etc. have extremely significant inhibitory effects on enzymes. The Km and Kcat of chitinase were determined to be 269.05 μ mol/L and 0.49 min-1, respectively. Chitinase PbCHI5 has
both endonuclease and exonuclease activity. The theoretical pI of the enzyme is 4.16, which is a stable hydrophilic protein. CONCLUSION: This experiment laid a theoretical foundation for the development and utilization of new low-temperature chitinases.
研究领域:
分子生物学
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生物化学
·
生物信息学
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酶学
·
海洋微生物学
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DOI
PubMed
高影响因子
ZEITSCHRIFT FUR NATURFORSCHUNG SECTION A-A JOURNAL OF PHYSICAL SCIENCES
·
2022
·Vol. 77
·期 12
·1217-1222
·
IF 1.712
Song Xie,Yushan Liu,Hongliang Chen,Xiaozhan Yang,Wenlin Feng
A cadmium ion (Cd 2+ ) sensor based on polyvinyl alcohol (PVA)/tetraethyl orthosilicate (TEOS)/3-aminopropyl triethoxysilane (APTES) film integrated Mach–Zehnder interferometer was fabricated and evaluated. The three core fiber (TCF) is spliced with two single mode fibers (SMFs), one end of TCF and SMF are spliced with enlarged taper, and the other end of TCF is directly spliced with another SMF. PVA/TEOS/APTES composite film is coated on the surface of TCF. When the Cd 2+ is adsorbed by the sensing film, the relative refractive index of TCF cladding changes, the output interference trough wavelength shifts. By monitoring the wavelength shift information of the interference trough, the concentration of Cd 2+ will be obtained. In the concentration range of 0–0.4 μM, with the increase of Cd 2+ concentration, the interference trough shows a red shift. The sensitivity and the detection limit of the sensor are 7 nm/μM and 0.0143 μM (1.6 ppb), respectively. The sensor has excellent selectivity and good pH stability. It has the advantages of easy preparation, simple structure, and has potential application for the detection of trace Cd 2+ .
研究领域:
光学传感
·
环境监测
·
材料科学
·
分析化学
✓ 已验证
DOI
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
·
2021
·
IF 3.493
Xiaolin Pei,Jiapao Wang,Haoteng Zheng,Qinjie Xiao,Anming Wang,Weike Su
The catalytically-active inclusion bodies (CatIBs) represent a promising strategy for immobilizing enzyme without additional carriers and chemicals, which has aroused great attention in academic and industrial communities. In this work, we discovered two natural parallel right-handed coiled-coil tetramer peptides from PDB database by a structural mining strategy. The two self-assembling peptides, NSPdoT from rotavirus and HVdoT from human Vasodilator-stimulated phosphoprotein, efficiently induced the CatIBs formation of a ( R )-Hydroxynitrile lyase from Arabidopsis thaliana ( At HNL) in Escherichia coli cells. This is convenient to simultaneously purify and immobilize the target proteins as biocatalysts. As expected, HVdoT- At HNL and NSPdoT- At HNL possessed drastically increased tolerance toward lower pH values, which will be very critical to synthesize cyanohydrins under acidic condition for suppressing the non-enzymatic side reaction. In addition. At HNL-CatIBs are produced at high yield in host cells as bioactive microparticles, which exhibited high thermal and pH stabilities. Therefore, the CatIBs method represent a promising application for the immobilization of enzymes in the biocatalysis field.
研究领域:
生物催化
·
酶工程
·
蛋白质科学
·
生物技术
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Jun Zeng,Gang Du,Xue Shao,Ke-Na Feng,Ying Zeng
Theaflavins (TFs) have attracted much attention due to their various bioactivities in black tea. This paper describes the first trial for enzymatic production of TFs by recombinant polyphenol oxidases (PPOs). PPO genes were cloned from nine species and expressed in E. coli . Crude enzyme assays by LC-MS revealed that eight recombinant PPOs were active for TFs production from tea polyphenols as substrates. Much higher activities were observed for crude enzymes of Md2 from Malus domestica (apple), Pp4 from Pyrus pashia (pear), and Ej2 from Eriobotrya japonica (loquat). When immobilized on mesoporous silica, crude Md2 was most active. The purified Md2 was immobilized and showed almost twice activity as high as its free enzyme. While the maximum activity of free enzyme was found at pH 5 and 10–30 °C, the immobilized enzyme had broader range of pH 4–6 and 10–40 °C. The activity of immobilized enzyme was relatively constant during the pH and thermal stability test. When used at 0.2 mg/ml in the beginning, the immobilized enzyme retained approximately 40% of its initial activity after 8 cycles of operation.
研究领域:
生物技术
·
酶学
·
食品科学
·
植物生化
✓ 已验证
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Liyue Zhang,Qiucheng Xu,Yanjie Hu,Ling Chen,Hao Jiang
Anion exchange membrane water electrolysis (AEMWE) is one of the most promising technologies for producing green hydrogen; however, they still suffer from durability issues. One task is to find suitable electrolyte conditions for anode catalysts that endow them with both high activity and stability. Herein, we benchmark the pH–stability relationship of four typical metal oxides as anode catalysts in the AEMWE. Their electrochemical performance and structural stability were in-depth analyzed through impedance, dissolved composition in the electrolyte, and correlated Pourbaix diagram. NiFe2O4 with the best activity and stability in the strong alkaline (pH = 14) shows terrible stability in pure water, which is then verified due to the severe Fe leaching, and it cannot be alleviated by alkaline pre-activation. Notably, Co3O4 shows comparable activity and stability to IrO2 in pure water and weak alkaline conditions. At pH = 12, it entails only ∼2.18 V to reach 1.0 A cm–2 and stabilizes for 40 h, being superior to others. This work screens out suitable transition metal oxides as a substitute for noble metals and their optimal application scenarios for AEMWE.
研究领域:
电化学
·
材料科学
·
可再生能源
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）