JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2015
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IF 2.912
Jie Long,Zhengzong Wu,Xingfei Li,Enbo Xu,Xueming Xu,Zhengyu Jin,Aiquan Jiao
We present a simple method to immobilize pullulanase onto hybrid magnetic (Fe3O4–κ-carrageenan) nanoparticles, involving the in situ synthesis of magnetic carrageenan nanoparticles and the formation of pullulanase/chitosan complex. The complex behavior of pullulanase with chitosan as a function of pH and protein–polysaccharide ratio was studied by turbidimetric titration. Then, the as-prepared immobilized enzymes were characterized by vibrating-sample magnetometer, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffractometer, and thermogravimetric analysis. It was found that the activity retention of immobilized pullulanase and amount of enzyme loaded reached 95.5% and 96.3 mg/g, respectively, under optimal conditions. The immobilized enzyme exhibited great operational stability (retaining approximately 61% residual activity after ten consecutive reuses), demonstrating that enzyme leakage during the catalysis reaction was efficiently reduced. Furthermore, the activity of immobilized pullulanase was significantly (p < 0.01) higher than that of free pullulanase in a low pH range (pH < 3.0) and temperature over 60 °C, and the immobilized enzymes retained 45% of their initial activity after 5 h at 60 °C, compared to 21% for the free enzyme. These results indicated that immobilized pullulanase was efficient in terms of catalytic activity and can be applied to continuous starch processing applications in the food industry.
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高影响因子
JOURNAL OF FOOD BIOCHEMISTRY
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2017
·Vol. 41
·期 5
·e12395
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IF 1
Shuai Cui,Qin-Wei Zhou,Xiao-Ling Wang,Si-Qi Yang,Kai Chen,Zhi-Yuan Dai,Yao-Wen Huang,Tao Zhou
Bovine pancreatic lipase was immobilized onto N -succinyl-chitosan beads by using N -(3-dimethylaminopropyl)- N ′-ethylcarbodiimide (EDC)/ N -hydroxysuccinimide (NHS) as the activating agent. The immobilized lipase was characterized by Fourier transform infrared spectra and scanning electron microscopy. The activity of the immobilized lipase obtained under the optimized immobilization conditions was found to reach 1,480 U/g, with enzyme activity recovery of 74.5%. Compared to the free lipase, thermal stability of the immobilized lipase was greatly improved. The reusability study indicated that the immobilized lipase retained 76.6% of its initial activity after being recycled five times. A preliminary study indicated that the prepared immobilized lipase can effectively enrich the polyunsaturated fatty acid in fish oil (increasing from 45.1 to 67.7%), of which the combined docosahexaenoic acid and eicosapentaenoic acid contents increased from 16.3 to 27.1%. Practical applications To overcome the drawbacks of using free lipase, an effective method was developed by immobilization of lipase onto N -succinyl-chitosan beads using EDC/NHS as the activating agent. The immobilized lipase prepared by this method may find application in the enrichment of polyunsaturated fatty acids of fish oil.
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APPLIED CLAY SCIENCE
·
2016
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IF 2.586
Zhujian Huang,Pingxiao Wu,Beini Gong,Xing Zhang,Zicong Liao,Pen-Chi Chiang,Xinjiang Hu,Lihua Cui
To further enhance the photocatalytic properties of doped-TiO 2 , a series of (N, Cu) co-doped TiO 2 /rectorite composites with different amount of N doping were prepared for adsorption and catalytic oxidation of p -chlorophenol ( p -CP) under visible light. The physicochemical properties of the obtained composites were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), etc. The results showed that the (N, Cu) co-doped TiO 2 catalyst was immobilized well onto rectorite , and the doping of N and Cu could affect the crystal structure of TiO 2 . The optimal N doping amount was determined by the photocatalytic degradation of p -CP in a stirred quartz reactor under visible light (> 420 nm) irradiation. It was found that the doping of N can improve significantly the degradation of p -CP and the optimum N doping amount is 1.0%. The adsorption of p -CP by the composites could accelerate the degradation rate of p -CP in situ. The photocatalytic activity of the (N, Cu) co-doped TiO 2 /rectorite composites remained stable after five cycles of photoreaction. A possible mechanism for the photocatalytic degradation of p -CP is proposed. Our work implied that rectorite has great potential to be applied in the field of photocatalysis .
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2024
·
IF 7.7
Huayang Tang,Yian Chen,Dexun Fan,Fengguang Zhao,Shuangyan Han
D-allulose, a low-calorie rare sugar catalyzed by D-allulose 3-epimerase (DAE), is highly sought after for its potential health benefits. However, poor reusability and stability of DAE limited its popularization in industrial applications. Although metal-organic frameworks (MOFs) offer a promising enzyme platform for enzyme immobilization, developing customized strategies for MOF immobilization of enzymes remains challenging. In this study, we introduce a designable strategy involving the construction of bimetal-organic frameworks (ZnCo-MOF) based on metal ions compatibility. The DAE@MOFs materials were prepared and characterized, and the immobilization of DAE and the enzymatic characteristics of the MOF-immobilized DAE were subsequently evaluated. Remarkably, DAE@ZnCo-MOF exhibited superior recyclability which could maintain 95 % relative activity after 8 consecutive cycles. The storage stability is significantly improved compared to the free form, with a relative activity of 116 % remaining after 30 days. Molecular docking was also employed to investigate the interaction between DAE and the components of MOFs synthesis. The results demonstrate that the DAE@ZnCo-MOF exhibited enhanced catalytic efficiency and increased stability. This study introduces a viable and adaptable MOF-based immobilization strategy for enzymes, which holds the potential to expand the implementation of enzyme biocatalysts in a multitude of disciplines.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Yixin Liu,Zhiping Sun,Cunhui Wu,Xinguang Qin,Gang Liu,Xinlin Wei,Haizhi Zhang
Exploring efficient immobilized carrier for α-Amylase (α-Amy) to enhance its thermostability has significant influence in starch related industry. Here, hollow ZIF-8 (HZIF-8) with amino groups coated magnetic phase change microcapsules (PCM) was designed for covalent immobilization of α-Amy. Magnetic PCM consisting n-docosane core and SiO 2 /Fe 3 O 4 hybrid shell were firstly synthesized. Then, HZIF-8 shell with amino groups was coated and α-Amy was subsequently immobilized through covalent cross-linking strategy. The morphology, chemical structure and magnetic property of PCM@HZIF-8@α-Amy (PCMHA) were comprehensively characterized. Moreover, heat control property of PCMHA was studied with encapsulation efficiency and thermal energy-storage efficiency of 50.55 % and 50.59 %, respectively. Catalytic activity of immobilized α-Amy was fully investigated with K m and V max of 2.773 mg/mL and 1.853 μmol/mL·min, respectively. From reusability and storage stability study, immobilized α-Amy not only maintained rather high activity after 9 cycles' reuse, but also exhibited good activity under high salt ion condition after 7 days.
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CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Qing Chang,Long Liu,Yaseen Muhammad,Shaoxia Weng,Zhenfei Feng,Tengyou Wei,Jingling Lei,Zhangfa Tong,Zhenxia Zhao
A magnetic Fe-N doped hollow acicular porous carbon (FeN-HAPC) with dopamine was successfully fabricated using a green free template-removal strategy for Lumbrukinase (LK) immobilization. FeN-HAPC was characterized by SEM , TEM , XRD, N 2 adsorption, XPS and FT-IR. Results revealed that immobilized LK through adsorption on FeN-HAPC possessed high activity (350 U/mg), good reusability (∼80% of initial value after 7th usage), and storage stability (86.0% at 4 °C for 30 days). Moreover, dopamine modification of FeN-HAPC ( [email protected] ) further significantly enhanced the amount and adsorption affinity towards immobilized LK, and thus exhibiting higher enzyme activity (617.5 U/mg) and reusable performance (87.3% for the 7th usage), and storage stability (92.4% at 4 °C for 30 days). Its deactivation half-life was 6–14 times longer than those immobilized over conventional Fe 3 O 4 microsphere or free ones. The deactivation energy of [email protected] /STI-LK was 146 kJ/mol, much higher than free LK and Fe 3 O 4 @CTS/STI-LK samples. Thus, the composite prepared in this study, attributed to possessing hollow structures with magnetic characteristic, high specific surface area, and high dispersion of affinity sites can be deemed as a promising candidate for enzyme adsorptive immobilization in practical applications.
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BIOCHEMICAL ENGINEERING JOURNAL
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2017
·
IF 2.892
Juan Han,Li Wang,Yun Wang,Jian Dong,Xu Tang,Liang Ni,Lei Wang
A geometrically symmetric four – arm dendritic polymer 4-arm-PEG-NH 2 was employed to modify on the surface of Fe 3 O 4 as support for cellulase immobilization. Glutaraldehyde was used as a coupling agent of this magnetic support to covalently immobilize cellulase. The morphology and properties of the synthesized magnetic material were characterized by Fourier transform infrared (FT-IR) spectroscopy, vibrating-sample magnetometer (VSM), thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The properties of immobilized enzyme such as the optimum temperature and pH, Michaelis constant, thermal stability, reusability and storage stability were investigated. The loading capacity of cellulase was 132 mg/g. Compared with free cellulase, immobilized cellulase showed wider pH and temperature ranges, higher operational stability and good storage stability. Besides, the results of hydrolysis filter paper and microcrystalline cellulose showed that the catalytic effect of immobilized cellulase on the free cellulase was increased by about 76%.
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JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2025
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IF 8.4
Xinyao Li,Liangzhong Li,Zhichao Huang,Zhaofeng Chang,Zhuo Tu,Luping Tian,Wei Du,Hao Li,Peng Zhang,Bo Pan
In the research on the preparation of biochar from co-pyrolysis of red mud (RM) and biomass, the synergistic mechanism of immobilizing heavy metals (HMs) and enhancing the stability of biochar is seldom reported. In this study, the effects of different mass ratios of corn stalks (CS) and RM (9:1, 3:1, 2:1, 1:1) and pyrolysis temperatures (300 °C, 450 °C, 600 °C) on the physicochemical properties, carbon stability, HMs speciation, and their potential risks were investigated. Furthermore, the mechanism of the co-pyrolysis process to enhance biochar stability and facilitate transformation of HMs speciation was analyzed. The results showed that co-pyrolysis of CS with RM significantly enhanced biochar's oxidation resistance (I D /I G = 0.61, R 50,biochar = 0.52), and simultaneously increased the stabilized state proportion of Ni, Cr, and Cd that exceed standard limits, thereby reduced the biochar phytotoxicity (GI = 193.20%). During the co-pyrolysis process, the metals and metal minerals in RM catalyzed the cleavage of CS, promoting the formation of condensed aromatic carbon structures in biochar, which adsorbed the free HMs to form organic carbon-metal/metal oxide complexes through coordination, achieving the dual roles of immobilizing HMs and enhancing the stability of biochar. In addition, the formation of large aggregates and the conversion of free HMs into metal oxides are important mechanisms for co-pyrolysis to enhance the biochar stability and HMs immobilization, respectively. This study provides a feasible and promising direction for the synergistic and efficient resource utilization of industrial and agricultural waste.
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高影响因子
FUEL
·
2025
·
IF 7.5
Dawei Wu,Aijia Zhang,Jing Liu,Yingju Yang
MFe 2 O 4 (M = Ca, Mn, Co, Ni, Cu and Zn) spinel sorbents were synthesized by a low-temperature sol–gel auto-combustion method for arsenic adsorption from flue gas. CuFe 2 O 4 spinel exhibited the highest arsenic removal performance among these sorbents, and the adsorption capacity reached 14.09 mg/g at 800 °C. The pseudo-first order, pseudo-second-order and Elovich kinetic models can well predict arsenic removal process, which indicates that the mass transfer and chemisorption processes are important during arsenic capture by CuFe 2 O 4 . The impact of incineration flue gas components on As 2 O 3 adsorption was elucidated. It was found that HCl showed negligible effect on arsenic removal by CuFe 2 O 4 sorbent while CO 2 , H 2 O, SO 2 and NO played inhibition roles. X-ray photoelectron spectroscopy results revealed that the adsorbed arsenic exists in the forms of As 3+ and As 5+ on the sorbent surface. The chemisorption and oxidation mechanisms are responsible for arsenic adsorption by CuFe 2 O 4 . The toxicity characteristic leaching procedure and sequential extraction experiments demonstrated that arsenic can be considerably immobilized in the CuFe 2 O 4 sorbent. The high arsenic capture capacity, excellent HCl resistance and low risk of secondary contamination make CuFe 2 O 4 an efficient sorbent for gaseous arsenic capture.
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TALANTA
·
2025
·
IF 6.1
Jinming Zhang,Jihang Zhang,Jiale Chen,Xiao Zhang,Jinglan Wu,Pengpeng Yang,Fengxia Zou,Hanjie Ying,Wei Zhuang
Enzyme immobilization techniques are crucial for enhancing enzyme stability and catalytic efficiency. Traditional methods such as physical adsorption and simple covalent binding often fail to maintain enzyme activity and stability. In this study, an innovative multi-level immobilization strategy was proposed to achieve efficient targeted immobilization of nuclease P1 (NP1) by fine-tuning the surface microenvironment. Molecular simulation results revealed that the distinctive electrostatic distribution and the specific placement of basic amino acids, such as lysine, on the NP1 surface caused dopamine to preferentially adsorb on areas away from NP1’s active site. This selective adsorption facilitated the directed immobilization of NP1, while the positively charged environment generated by the co-deposited surface further enhanced NP1’s adsorption capacity. This multilevel modification was found to significantly optimize the physicochemical environment of the immobilized surface through surface characterization and enzymatic testing. This strategy greatly improves enzyme activity (3590.0 U/mg), stability, and reusability (70 % after 10 cycles). In particular, NP1 on this surface exhibited an optimal Michaelis constant (K m ) of 34.0 mM and a maximum reaction rate of 5.5 mM min −1 , demonstrating the remarkable effect of the modification strategy in enhancing the enzyme catalytic performance. The present study provides an efficient and stable immobilization platform for enzyme catalytic applications by precisely modulating the surface microenvironment and the oriented immobilization strategy, which has an important potential for practical applications. This stable and reusable NP1 platform allows for efficient DNA/RNA cleavage, facilitating its application in industrial biocatalysis, biomedical enzyme-based processes, and biosensors.
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高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Liangqiang Chen,Mengdi Hao,Wanqiu Huang,Shaoning Yu,Hao Shen,Fan Yang,Li Wang,Huabin Tu
Multiple enzymes induce biological cascade catalysis is essential in nature and industrial production. However, the shortcomings of enzymes, including unsatisfactory stability, reusability, and sensitivity in harsh microenvironment, have restricted their broader use. Here, we report a facile method for fabricating a cascade system by combining the benefits of immobilized enzymes and biomimetic catalysis based on magnetic metal–organic framework nanoflowers (mMOFNFs). mMOFNFs prepared through the layered double hydroxide-derived strategy exhibited remarkable peroxidase-like activity and accessible amino interface, enabling it to serve not only as a reliable carrier for α-glucosidase and glucose oxidase fixation, but also as a nanozyme participating in cascade. On this basis, a colorimetric biosensor of excellent sensitivity and selectivity for α-amylase detection was constructed with a wide range (2–225 U L −1 ), low detection limit (2.48 U L −1 ), and rapid operation (30 min). This work provides a versatile strategy for establishing multi-enzyme cascade systems and rapid analysis of α-amylase.
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高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Rihong Xiao,Jianping Yang,Yili Zhang,Zhuo Xiong,Junying Zhang,Yongchun Zhao
Industrial flue gas mercury emissions account for 30% of global atmospheric mercury emissions. While selenium-based materials show potential in reducing mercury emissions, the aspect of mercury recovery is neglected amidst the pressing need for mercury resources. Unlike conventional adsorbent regeneration cycles, elemental selenium anchoring mercury directly yields valuable by-products such as HgSe, a semiconductor with a narrow bandgap, considered ideal for optoelectronic devices. Amorphous selenium (α-Se) exhibits high mercury removal efficiency at room temperature but converts to less active trigonal selenium (t-Se) in high-temperature industrial flue gas. The literature on the mercury removal behavior of t-Se is limited. To address this issue, rod-shaped selenium (Se-rod) with specific exposed active crystal facets (101) and vacancy defects is synthesized, achieving an exceptional mercury adsorption capacity of 430.10 mg g −1 . Moreover, the optical performance of self-produced HgSe surpasses those of commercial samples. Se-rod can be utilized for mercury removal while also bridging the gap in mercury resource supply.
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