Foods
·
2025
·Vol. 14
·期 9
·1538
·
IF 5.1
Zepeng Li,Runmin Wang,Xiantai Lai,Wenyi Liao,Runfeng Liao,Zhuohong Wu,Guoyan Zhang,Xianghui Qi
D-tagatose is a functional sweetener with glucose-regulating and prebiotic properties, but its bioproduction from D-galactose faces many limitations, particularly the high production costs. In particular, the current biosynthesis of D-tagatose suffers from thermal instability and the substrate selectivity issues of L-arabinose isomerase (L-AI) required to convert D-galactose into D-tagatose. In this study, recombinantEscherichia coliBW25113/pQE-80L-araAF118M/F279Iexpressing double mutant L-AI was immobilized to enhance its stability and reusability. The optimal conditions for whole-cell catalysis were 60 °C, pH 6.5, 5 mM Mn2+, and 20 h, with a yield of 55.2 g/L of D-tagatose. Immobilization with 3% sodium alginate and 2% CaCl2retained 90% of the production efficiency displayed by free cells. Notably, the immobilized cells exhibited enhanced heat resistance (60–70 °C) and operational stability, retaining 76% activity after five cycles. The D-tagatose production was further increased to 129.43 g/L by increasing the substrate concentration to 250 g/L. Compared to free cells, immobilized cells retained 83.6% of the initial yield up to 10 batches. This study presents a cost-effective and sustainable method for the production of D-tagatose using optimized whole-cell catalysis through immobilization, which paves the way to solve industrial challenges such as thermal instability and low substrate efficiency.
研究领域:
生物化学
·
食品科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2022
·Vol. 12
·期 5
·521
·
IF 4.501
M. Abdur Rahaman,Bibimaryam Mousavi,Farah Naz,Francis Verpoort
Here, for the first time, a 2D and leaf-like zeolitic imidazolate framework (ZIF-L) is reported for the synthesis of ultrahigh molecular weight (UHMW) poly(methyl methacrylate) (PMMA) withMnup to 1390 kg mol−1. This synthesis method is a one-step process without any co-catalyst in a solvent-free medium. SEM, PXRD, FT-IR, TGA, and nitrogen sorption measurements confirmed the 2D and leaf-like structure of ZIF-L. The results of PXRD, SEM, TGA demonstrate that the catalyst ZIF-L is remarkably stable even after a long-time polymerization reaction. Zwitterionic Lewis pair polymerization (LPP) has been proposed for the catalytic performance of ZIF-L on methyl methacrylate (MMA) polymerization. This MMA polymerization is consistent with a living system, where ZIF-L could reinitiate the polymerization and propagates the process by gradually growing the polymer chains.Keywords:ultrahigh molecular weight polymer;poly methyl methacrylate;heterogeneous catalyst;zeolitic imidozolate framework
研究领域:
材料科学
·
高分子化学
·
催化
✓ 已验证
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 28
·17005-17019
·
IF 3.108
Shifeng Yan,Taotao Wang,Xing Li,Yuhang Jian,Kunxi Zhang,Guifei Li,Jingbo Yin
Injectable hydrogels as an important biomaterial class have been widely used in regenerative medicine. A series of injectable poly(L-glutamic acid)/chitosan (PLGA/CS) hydrogels were fabricated by self-crosslinking aldehyde-modified PLGA (PLGA–CHO) and lactic acid-modified chitosan (CS–LA). The oxidation degree of PLGA–CHO and degree of substitution (DS) of CS–LA could be adjusted by the amount of sodium periodate and lactic acid, respectively. The effect of the solid content of the hydrogels, oxidation degree of PLGA–CHO and CS–LA/PLGA–CHO mass ratio on the gelation time, gel content, water uptake, mechanical properties, microscopic morphology, and in vitro degradation of the hydrogels was examined. The pH and ion sensitivity of PLGA/CS hydrogels was also examined. Encapsulation of rabbit chondrocytes within the hydrogels showed viability of the entrapped cells and cytocompatibility of the injectable hydrogels. The injectable PLGA/CS hydrogels demonstrated attractive properties for future application in pharmaceutical delivery and tissue engineering.
研究领域:
生物材料
·
再生医学
·
高分子科学
·
生物医学工程
·
细胞生物学
✓ 已验证
DOI
高影响因子
CATALYSIS LETTERS
·
2021
·Vol. 152
·期 4
·1160-1169
·
IF 3.186
Cheng Lin,Cao Liumei,Ren Hao,Guo Qiaoqiao,Deng Huifang,Li Yiming
The construction of a multifunctional catalyst for multistep sequential\tandem reactions at the molecular level faces a formidable challenge. Multivariate (MTV)-MOFs can provide a facile and tunable platform for rationally designing such multifunctional catalysts via grafting different catalytic groups on the bridging ligands. However, the related investigations are still limited. Here, Pd(II) and l -proline are metalated and decorated to organic linkers, respectively, to build a MTV-MOF, which is then successfully applied to sequential Suzuki Coupling/asymmetric Aldol reactions with satisfied coupling performance (yields up to 99%) and good enantioselectivities ( ee anti up to 98%). Inductively coupled plasma optical emission spectrometer (ICP-OES) measurements of the supernatant and hot leaching test suggest the heterogeneous nature of the catalyst. Macrosubstrate tests verify that the reaction occurs inside the pores of the MOF. The heterogeneous catalyst can maintain structural stability and catalytic activity within three cycles. Graphic Abstract Versatile Pd(II) and l -proline were metalated and decorated, respectively, into stable UiO-67 to construct bifunctional and heterogeneous multivariate MOF catalyst, which displayed efficient and recyclable catalytic activity in sequential Suzuki Coupling/asymmetric Aldol reactions.
研究领域:
化学
·
材料科学
·
催化领域
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2023
·
IF 5.2
Chao Su,Bin Pei,Peilun Shen,Qifang Zheng,Jinpeng Cai,Dianwen Liu
To solve the problem of depression failure caused by xanthate pre-adsorption, this paper comprehensively studies the mechanism and characteristics of L -cysteine (L-C) adsorption on the surface of galena with or without xanthate through micro-flotation, X-ray photoelectron spectroscopy (XPS), inductively coupled plasma-optical emission spectrometry (ICP-OES), field emission scanning electron microscope-energy dispersive spectroscopy (FESEM-EDS), time of flight secondary ion mass spectrometry (ToF-SIMS), zeta potential , UV–visible spectrum, and contact angle experiments. SBX has a significant effect on the adsorption behavior of L-C on the surface of galena. The micro-flotation results showed that the L-C has very good depression effect on galena. However, this is invalid when sodium butyl xanthate (SBX) is preferentially introduced. L-C can be adsorbed on galena through the reaction of -SH and -NH 2 with exposed lead sites. In addition, the lead species dissolved from the surface of galena can be re-adsorbed after complexing with L-C in solution. However, L-C can hardly interact with the surface of galena pre-treated by SBX, and it is only adsorbed by electrostatic force in the form of [Pb(C 3 H 7 NO 2 S)] 2+ and [PbOH(C 3 H 7 NO 2 S)] + complexes. This study is expected to achieve cyanide free separation of Cu-Pb bulk concentrate.
研究领域:
矿物加工工程
·
表面化学
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2015
·Vol. 19
·期 12
·3613-3620
·
IF 2.446
Yang Suling,Li Gang,Wang Guifang,Deng Dehua,Qu Lingbo
A novel electrochemical sensor based on Fe 2 O 3 nanoparticles supported on N-doped graphene (Fe 2 O 3 NPs/N–GR) has been fabricated for electrocatalytic oxidation and detection of L-cysteine. The Fe 2 O 3 NPs/N–GR was characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS), and electrochemical methods. The electrochemical behavior of L-cysteine at Fe 2 O 3 NPs/N–GR was investigated by voltammetry. The Fe 2 O 3 NPs/N–GR showed a very efficient electrocatalytic activity for the oxidation of L-cysteine in 0.1 M phosphate buffer solution (PBS, pH 7.0). The oxidation peak currents increased dramatically at Fe 2 O 3 NPs/N–GR-modified electrode. The potential utility of the sensor was demonstrated by applying it to the analytical determination of L-cysteine. Experimental results showed that the electrocatalytic current increased linearly with L-cysteine concentration in the range of 0.2–400 μM with a lowest detectable concentration of 0.1 μM.
研究领域:
分析化学
·
生物医学工程
·
材料科学
✓ 已验证
DOI
高影响因子
Marine Life Science & Technology
·
2025
·
IF 5.3
Wang Yan,Wang Zhen,Zhao Wen-Xiao,Yuan Xiao-Jie,Yu Yang,Wang Peng,Wang Min,McMinn Andrew,Zhang Yu-Zhong,Peng Ming,Fu Hui-Hui,Chen Xiu-Lan
Free trans -4-hydroxy-L-proline (T4LHyp), a non-proteinogenic amino acid, is mainly released from the degradation of collagen, hydroxyproline-rich glycoproteins, and some peptide antibiotics in nature. Although it has been known that some terrestrial bacteria utilize T4LHyp as carbon and nitrogen source via a T4LHyp gene cluster, which and how marine microorganisms catabolize T4LHyp still remains unclear. Here, five T4LHyp-utilizing marine bacterial strains, Halomonas sp. 5021, Salinicola sp. 4072, Alteromonas sp. 6022, Alteromonas sp. 5112 and Alteromonas sp. 30521, were isolated from hydrothermal vent sediment samples collected from the southwest Indian Ocean. While Halomonas sp. 5021 can utilize T4LHyp as both a nitrogen and carbon source, the other four strains can utilize T4LHyp as only a nitrogen source. Then, the T4LHyp catabolic mechanisms of Halomonas sp. 5021 and Salinicola sp. 4072, as a representative of the four strains, were further investigated by genomic, transcriptional, and biochemical analyses. Halomonas sp. 5021 adopts an intact T4LHyp gene cluster containing four enzymes to catabolize T4LHyp into NH 3 and α-ketoglutarate to provide nitrogen and carbon sources for its growth. Compared to Halomonas sp. 5021, Salinicola sp. 4072 lacks an α-KGSA dehydrogenase gene in the T4LHyp gene cluster and can only catabolize T4LHyp into NH 3 and α-ketoglutarate semialdehyde to provide a nitrogen source for its growth. Bioinformatic investigation showed that the 5021-like and 4072-like T4LHyp gene clusters are predominantly found in bacteria from Pseudomonadota , which are widely distributed in multiple marine habitats. Thus, Pseudomonadota bacteria are likely the dominant group to drive the recycling and mineralization of T4LHyp in the ocean.
研究领域:
海洋微生物学
·
微生物生态学
·
生物化学
·
基因组学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
·
2020
·
IF 2.69
Yasong Hu,Congcong Zhan,Anduo Zhou,Shanfeng Zhang,Juying Chen,Xia Huang
A novel amino acid-modified biomacromolecule was designed and synthesized as the quaternary ammonium salt chitosan grafted-tyrosine (CA-g-Tyr) suitable for biomedical applications. L-tyrosine was grafted onto the quaternary ammonium salt chitosan (CA) by N-(3-dimethylaminopropy)-N-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). The chemical structure of CA-g-Tyr was confirmed by Fourier transform infrared (FTIR) spectroscopy and 13C-NMR. The change in the crystalline structure after the graft was characterized by differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). The surface wettability and moisturizing performance of the CA-g-Tyr were also characterized. The CA-g-Tyr film possessed good hydrophilicity, and the mechanical tensile experiments showed that the introduction of tyrosine gave CA mechanical properties more suitable for blood vessel. Cell experiments showed that the endothelial cells can adhere and proliferate better on the surface of a CA-g-Tyr film than CA. The results confirm the favorable properties and biocompatibility of CA–g-Tyr with potential applications as scaffolds for tissue engineering.
研究领域:
生物材料学
·
医学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2018
·Vol. 185
·期 9
·1-13
·
IF 5.705
Wang Jiangru,Yu Jialuo,Wang Xiaoyan,Wang Liyan,Li Bowei,Shen Dazhong,Kang Qi,Chen Lingxin
Manganese-doped ZnS quantum dots (ZnS:Mn(II) QDs) were synthesized and modified with L-cysteine (L-Cys) and 6-mercaptonicotinic acid (MNA). This prevents the aggregation of the QDs and makes them available for the interaction with Cu(II) ions via Cu(II)-S interaction. As a result, the fluorescence of the QDs is quenched by Cu(II) due to an electron transfer mechanism. The QDs display two emission peaks under 325 nm excitation, one (being red) peaking at 593 nm, the other (blue) at 412 nm. The red fluorescence is strongly quenched, while the blue fluorescence is not affected. An easily distinguishable color change from orange red to purple can be observed in fluorescence as the concentration of Cu(II) is increased. The probe is selective over commonly encountered other ions. The ratio of fluorescence intensities at 593 and 412 nm increases linearly in the 5 to 500 nM Cu(II) concentration range, and the detection limit is 1.2 nM.
Schematic of the preparation of manganese-doped quantum dots functionalized with L-cysteine and 6-mercaptonicotinic acid for selective and sensitive visual detection of copper ions.
研究领域:
分析化学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Xia Wang,Xuan Zhang,Cai Gao,Xiaolei Liao,Le Hang,Shulian Jiang,Feng Gao,Lizhang Huang,Qingxiang Wang
A novel electrochemical DNA biosensor based on in-situ labeling of L -Aspartic acid-copper ion (Asp-Cu 2+ ) complex on the terminal of molecule beacons (MBs) was constructed. The MB with bifunctional groups of 3’–SH and 5’–COOH was first anchored on a gold electrode surface through Au-S assembly chemistry, then L -Aspartic acid (Asp) was grafted with the 5’–COOH of MB via succinimide coupling, which was used as a platform molecule for the following coordination assembly of copper ions (Cu 2+ ). Therefore an electroactive MBs probe with the copper complex (Asp-Cu 2+ ) as a signal source was obtained. The hybridization between the loop sequence and the target DNA transferred the hairpin-like MBs to the linear form, and the electroactive moiety of Asp-Cu 2+ was forced to leave away from the electrode surface, resulting in the reduction of the electrochemical response of the biosensor. The hybridization experiment results showed that the oxidation peak currents of developed biosensor attenuated linearly with the logarithmic values of the target DNA concentrations in the kinetic range from 1.0×10 -15 ~1.0×10 -10 M. The detection limit was estimated to be 0.17 fM. Moreover, the biosensor showed excellent selectivity for discriminating the complementary sequences from the mismatched and noncomplementary sequences.
研究领域:
生物化学
·
分子生物学
✓ 已验证
DOI
高影响因子
Materials Chemistry Frontiers
·
2016
·Vol. 1
·期 4
·660-667
·
IF 0
Xianfeng Hou,Jin Peng,Fang Zeng,Changmin Yu,Shuizhu Wu
Alpha-L-fucosidase (AFU) plays vital roles in some physiological processes that closely relate to several diseases. Herein, a ratiometric fluorescent probe for the alpha-L-fucosidase (AFU) assay based on a single fluorophore has been developed by functionalizing a new fluorophore platform (6-bromo-anthracenecarboximide) with an α-L-fucose group. AFU cleaves the α-L-fucose group from the probe molecule and remarkably alters its photophysical properties, thus realizing ratiometric detection of AFU. Due to the specificity and high efficiency of the enzymatic reaction, this probe can sensitively and selectively detect AFU in aqueous media and biological milieus with a detection limit of 0.0033 U mL−1. Moreover, the probe can be employed to monitor and spatially map endogenous AFU levels in a hepatocellular carcinoma (HCC) model of zebrafish. Hence, the probe holds significant promise for conducting pathological research on AFU-involved diseases.
研究领域:
生物化学
·
医学诊断
·
分子生物学
✓ 已验证
DOI
FOOD CHEMISTRY
·
2025
·
IF 9.8
Yuanxiu Liu,Tong Shi,Xiyue Cao,Xin Wang,Mengzhe Li,Chenya Lu,Xiaoli Zhang,Ying Tian,Li Yuan,Wengang Jin,Ruichang Gao
This study explored the influences of L-Arg in the ion migration and the quality of low-salt fish balls (L, 0.3 % NaCl). L-Arg significantly increased the weight gain and expansion rate of L by 18.33 % and 13.47 %. Water-holding capacity decreased from the internal to the external part of fish balls, consistent with the looser microstructure. Inductively coupled plasma-mass spectrometry (ICP-MS) revealed that L-Arg promoted Na + migration at setting ( P < 0.05), decreased the internal concentration from 34.38 to 30.37 mg/L and increased the external one from 25.78 to 29.80 mg/L ( P < 0.05). Conversely, Cl − concentration was decreased at setting and improved after the two-stage heating ( P < 0.05), indicating the suppressed Cl − migration. The partial replacement of Na + by L-Arg facilitated the protein unfolding, formation of disulfide bonds and exposure of tryptophan residues. This study enriched the mechanisms of salt reduction and quality maintenance for surimi products regarding ion migration.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）