JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2024
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IF 5.7
Chenlu Zhu,Renjiao Han,Bixuan Gu,Caiyun Wang,Han Liu,Xiaomei Lyu,Jian He,Ruijin Yang
The limited expression of cellobiose 2-epimerase poses a significant constraint on the industrial enzymatic production of lactulose. Extensive modifications to the expression cassette offer a means to enhance the yield of recombinant proteins. In this study, an integrated strategy, combining individual and collaborative approaches, is proposed to fine-tune each stage of the CsCE overexpression program. This strategy involves the multidimensional integration of standardized genetic elements at various levels, including transcription, translation, folding, and three-dimensional structure. The volumetric activity of the final recombinant strain was markedly increased by 12-fold compared to the wild-type strain, reaching 2260.62 U/L. The protein expression in the newly developed high-yield recombinant strain exhibited a significant enhancement, with a higher proportion of soluble protein compared to that of inclusion bodies. Our findings offer insights into the multifaceted synergistic regulation of protein expression processes, holding promising implications for the production of heterologous recombinant proteins.
研究领域:
生物工程
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分子生物学
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DOI
PubMed
高影响因子
Food Bioscience
·
2025
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IF 5.9
Chenlu Zhu,Jian He,Jiali Gu,Xiaomei Lyu,Renjiao Han,Han Liu,Caiyun Wang,Ruijin Yang
Directed evolution of the active pocket is particularly effective for altering the substrate specificity of enzymes. Herein, we investigate the feasibility of lactulose synthesis by glucose isomerase based on re-sharping the active pocket. The glucose isomerase from Streptomyces sp. SK ( SK GI) was found possessing the activity to isomerize lactose. Based on this discovery, directed evolution of SK GI was performed via re-construction of the substrate binding pocket to improve its substrate specificity of towards lactose. As a result, the variant SK GI (N215C/K289R) with higher production (3.33-fold improvement) and longer half-life (increased from 196.92 min to 278.37 min) was obtained. These findings will provide new research perspectives for the directed evolution of enzymes. In the future, they will drive enzymes to evolve new functions by overcoming catalytic limitations.
研究领域:
生物化学
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酶工程
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合成生物学
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DOI
高影响因子
BIOPROCESS AND BIOSYSTEMS ENGINEERING
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2023
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IF 3.8
Jia Dong-Xu,Yu Hai,Wang Fan,Jin Li-Qun,Liu Zhi-Qiang,Zheng Yu-Guo
Cellobiose 2-epimerase (CE) is ideally suited to synthesize lactulose from lactose, but the poor thermostability and catalytic efficiency restrict enzymatic application. Herein, a non-characterized CE originating from Caldicellulosiruptor morganii (CmCE) was discovered in the NCBI database. Then, a smart mutation library was constructed based on FoldX ΔΔG calculation and modeling structure analysis, from which a positive mutant D226G located within the α 8 /α 9 loop exhibited longer half-lives at 65–75 °C as well as lower K m and higher k cat / K m values compared with CmCE. Molecular modeling demonstrated that the improvement of D226G was largely attributed to the rigidification of the flexible loop, the compactness of the catalysis pocket and the increment of substrate-binding capability. Finally, the yield of synthesizing lactulose catalyzed by D226G reached 45.5%, higher than the 35.9% achieved with CmCE. The disclosed effect of the flexible loop on enzymatic stability and catalysis provides insight to redesign efficient CEs to biosynthesize lactulose. Graphical abstract
研究领域:
生物技术
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酶学
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分子生物学
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化学工程
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2024
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IF 7.7
Hu Xu,Mukan Ji,Dawei Xu,Yongqin Liu
Cellobiose 2-epimerase (CE) catalyzes the conversion of the lactose into its high-value derivatives, epilactose and lactulose, which has great prospects in food applications. In this study, CE sequences from the Qinghai-Tibet Plateau gene catalogue, we screened these for structural flexibility through molecular dynamics simulation to identify potential psychrophilic CE candidates. One such psychrophilic CE we termed psyCE demonstrated exceptional epimerization activity, achieving an optimum activity of 122.2 ± 1.6 U/mg. Its kinetic parameters (K cat and K m ) for epimerization activity were 219.9 ± 5.6 s −1 and 261.9 ± 18.1 mM, respectively, representing the highest K cat recorded among known cold-active CEs. Notably, this is the first report of a psychrophilic CE. The psyCE can effectively produce epilactose at 8 °C, converting 20.3 % of 200 mM lactose into epilactose within four hours. These findings suggest that psyCE is highly suitable for cryogenic food processing, and glaciers may serve as a valuable repository of psychrophilic enzymes.
研究领域:
生物化学
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酶学
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食品科学
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DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2025
·Vol. 13
·期 24
·18814-18823
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IF 9.5
Zhiyong Liao,Ruizhe Zhang,Yongbo Fan,Lixing Song,Fang Yan,Ning Yang,Peizhi Dong,Zhuo Zhang,Zexue Lin,Weijia Wang,Huiqing Fan
The performance of zinc metal anodes in aqueous zinc-ion batteries (AZIBs) is strongly influenced by the chemical composition of the inner Helmholtz plane (IHP), which plays a critical role in ensuring anode stability and reversibility. In aqueous environments, a water-dominant IHP induces undesirable side reactions and irregular zinc deposition, presenting significant challenges for the practical application of zinc anodes. This study introduces lactulose (LA), a polyhydroxy sugar, as a self-adsorptive additive to modify the IHP. LA effectively displaces water molecules, forming a drier IHP that mitigates water-induced decomposition reactions and improves the stability of the zinc anode. Moreover, LA adsorption promotes Zn (002) plane nucleation, effectively inhibiting dendrite formation and enhancing the reversibility of the zinc anode. As a result, the Zn‖Zn symmetric cell achieves stable operation for over 2200 hours at 1 mA cm−2 and 0.5 mA h cm−2. The Zn‖Cu half-cell demonstrates stable cycling performance, completing more than 1000 cycles with a coulombic efficiency of 99.4%. Similarly, the Zn‖MnO2 full cell retains 85.31% of its initial capacity following 1100 cycles at a charge/discharge rate of 1 A g−1. Under the same conditions, the Zn‖MnO2 pouch cell retains 77.63% of its capacity after 480 cycles. These results underscore the significant potential of LA as an additive for enhancing the practical viability of zinc-ion batteries.
研究领域:
电化学
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能源材料
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电池技术
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界面化学
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电沉积
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产品关联
DOI
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
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2024
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IF 3.4
Bohua Wang,Song Lei,Qingqin Li,Yushuang Luo
Lactulose is a semisynthetic nondigestive sugar derived from lactose, with wide applications in the food and pharmaceutical industries. Its biological production routes which use cellobiose 2-epimerase (C2E) as the key enzyme have attracted widespread attention. In this study, a set of C2Es from different sources were overexpressed in Escherichia coli to produce lactulose. We obtained a novel and highly efficient C2E from Clostridium disporicum (CDC2E) to synthesize lactulose from lactose. The effects of different heat treatment conditions, reaction pH, reaction temperature, and substrate concentrations were investigated. Under the optimum biotransformation conditions, the final concentration of lactulose was up to 1.45 M (496.3 g/L), with a lactose conversion rate of 72.5 %. This study provides a novel C2E for the biosynthesis of lactulose from low-cost lactose.
研究领域:
生物技术
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食品科学
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药学
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酶学
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DOI
PubMed
高影响因子
EUROPEAN JOURNAL OF PHARMACEUTICAL SCIENCES
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2020
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IF 3.616
Xiaoyu Zhang,Junping Zheng,Nan Jiang,Guangjun Sun,Xinkun Bao,Mingwang Kong,Xue Cheng,Aizhen Lin,Hongtao Liu
Lactulose is a common laxative and has been widely applied to clinical treatment for constipation. This study aimed to explore the improving effect of lactulose on constipation through the mediation of gut microbiota and intestinal metabolites. BALB/c mice with constipation induced by loperamide were orally treated with lactulose for four weeks. After the treatment, the constipation-related factors were determined. The effect of lactulose on the composition of gut microbiota was assessed by 16S rDNA gene sequencing. Gas chromatography or liquid chromatography-mass spectrometer (GC/LC-MS) analysis was used for the quantification of intestinal metabolites. The treatment of constipated mice with lactulose accelerated intestinal motility, suppressed inflammatory responses, protected gut barrier, and improved metabolisms of water and salt in the intestinal tract. These therapeutic effects were attributed to the reversed gut microbiota dysfunction, which conferred the benefit to the production of intestinal metabolites including bile acids, short-chain fatty acids, and tryptophan catabolites. Further, the depletion of intestinal flora from loperamide- or (loperamide + lactulose)-treated mice confirmed the significance of gut microbiota in the mediation of constipation. In summary, this study leads us to propose that lactulose may improve constipation through a prebiotic effect on gut microbiota and intestinal metabolites.
研究领域:
胃肠病学
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微生物学
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药理学
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代谢组学
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DOI
PubMed
高影响因子
Brain and Behavior
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2024
·Vol. 14
·期 7
·e3621
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IF 2.6
Xiang Kong,Song Luo,Shi Yao Wu,Jun Zhang,Gui Fen Yang,Guang Ming Lu,Long Jiang Zhang
Introduction Hepatic encephalopathy (HE) is a severe neuropsychiatric complication of liver diseases characterized by neuroinflammation. The efficacies of nonabsorbable rifaximin (RIF) and lactulose (LAC) have been well documented in the treatment of HE. [ 18 F]PBR146 is a translocator protein (TSPO) radiotracer used for in vivo neuroinflammation imaging. This study investigated anti-neuroinflammation effect of RIF or/and LAC in chronic HE rats by [ 18 F]PBR146 micro-PET/CT. Methods Bile duct ligation (BDL) operation induced chronic HE models, and this study included Sham+normal saline (NS), BDL+NS, BDL+RIF, BDL+LAC, and BDL+RIF+LAC groups. Behavioral assessment was performed to analyze the motor function, and fecal samples were collected after successfully established the chronic HE model (more than 28 days post-surgery). In addition, fecal samples collection and micro-PET/CT scans were performed sequentially. And we also collected the blood plasma, liver, intestinal, and brain samples after sacrificing the rats for further biochemical and pathological analyses. Results The RIF- and/or LAC-treated BDL rats showed similar behavioral results with Sham+NS group, while the treatment could not reverse the biliary obstruction resulting in sustained liver injury. The RIF or/and LAC treatments can inhibit IFN-γ and IL-10 productions. The global brain uptake values of [ 18 F]PBR146 in BDL+NS group was significantly higher than other groups ( p < .0001). The brain regions analysis showed that the basal ganglia, hippocampus, and cingulate cortex had radiotracer uptake differences among groups (all p < .05), which were consistent with the brain immunohistochemistry results. Sham+NS group was mainly enriched in Christensenella, Coprobacillus, and Pseudoflavonifractor. BDL+NS group was mainly enriched in Barnesiella, Alloprevotella, Enterococcus, and Enterorhabdus. BDL+RIF+LAC group was enriched in Parabacteroides, Bacteroides, Allobaculum, Bifidobacterium, and Parasutterella. Conclusions RIF or/and LAC had anti-neuroinflammation in BDL-induced chronic HE rats with gut microbiota alterations. The [ 18 F]PBR146 could be used for monitoring RIF or/and LAC treatment efficacy of chronic HE rats.
研究领域:
肝病学
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神经病学
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药理学
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影像科学
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微生物学
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DOI
PubMed
高影响因子
Food Bioscience
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2024
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IF 4.8
Juncheng Liu,Xingyu Lu,Fang Fang,Kaizhang Wu,Jihong Wu,Jie Gao
This study aimed to compare the effects of sodium alginate (SA), galactooligosaccharides (GOS), lactulose (LC), polydextrose (PDX), and inulin (IN) on gut microbiome and metabolome using stable in vitro human gut fermentation model. The five prebiotics with different structure were effective in promoting beneficial bacteria, such as increased Bifidobacterium , Enterococcus , and Ruminococcaceae_UCG_014 in the GOS group, and Parabacteroides and Phascolarctobacterium in the PDX group. Also, prebiotics promoted total short chain fatty acids (SCFAs) production, especially the butyric acid increased by SA with the largest molecular weight and high content of ManA. Most prebiotics affected carbohydrate metabolism, amino acid metabolism, and lipid metabolism pathways. The changed metabolic pathways were similar between the LC and GOS with the smallest molecular weight, and IN and PDX with analogous molecular weight and monosaccharide composition were strongly associated with energy metabolism pathways. This paper could promote the application and development of prebiotics in food industry.
研究领域:
食品科学
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微生物学
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营养学
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代谢组学
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DOI
高影响因子
Analytical Methods
·
2024
·Vol. 16
·期 22
·3551-3561
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IF 2.7
Kaigang An,Xin Li,Jia Chen,Shuang Zhang,Jing Xiao,Qing Wang,Hongdeng Qiu
Tetracycline (TC) as a broad-spectrum antibiotic, is widely used in the prevention and treatment of various bacterial diseases. However, its abuse in the livestock industry may lead to interference in human microecology, thereby causing various side effects. In this study, deep eutectic solvents (DESs) were synthesized using L-(–)-threonine (L-(–)-Thr) and cerium nitrate hexahydrate (Ce(NO3)3·6H2O), and later lanthanum nitrate hexahydrate (La(NO3)3·6H2O) was doped to synthesize La–Ce hybrid nanorods. These nanorods can be used for the determination of TC with high sensitivity and selectivity by the colorimetric method. This approach has a linear response to TC between 0.05 μM and 10 μM, with a detection limit of 0.016 μM. In this system, good dispersion provides the substance with a distinct peroxidase activity, which is used to create a colorimetric sensor for detecting TC. Mechanism studies show that the superoxide radical generated by the La–Ce nanomembrane plays a key role in peroxidase catalysis. Finally, the practicality of the method was verified by the determination of TC in food products (milk, pork and honey), which demonstrated that a good recovery rate can be obtained (91.4–102%).
研究领域:
分析化学
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食品安全
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纳米材料科学
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DOI
PubMed
高影响因子
WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY
·
2025
·Vol. 41
·期 11
·451
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IF 4.2
Zhong Chenggang,Ding Weijian,Lin Haoran,Huang Jin
Cellobiose-2-epimerase is considered an ideal biocatalyst for the strictly thermodynamic synthesis of lactulose. However, its poor thermolability limits its industrial application. Herein, we successfully developed a novel thermostable cellobiose-2-epimerase for improving lactulose biosynthesis from lactose. The A242L mutant, derived from Dictyoglomus thermophilum (DiCE), was generated using semi-rational mutagenesis after computer-aided design via the FireProt web server. After systematic enzymatic characterization and optimization, A242L mutant exhibited a 123.5% T 1/2 in thermostability at 80 °C relative to the wild-type enzyme, and the E. coli BL21/pET28a(+)-A242L mutant harvested a maximal lactulose yield of 64.52%, representing a 51.38% improvement at a substrate concentration of 200 g/L for the whole-cell biotransformation reaction conducted at pH 7.0 and 80 °C for 4 h. Molecular docking and molecular dynamics (MD) simulation results indicated that the enhanced thermostability of the enzyme was closely related to the structure and rigidity of its flexible loops. The enhanced thermostability allows A242L to tolerate higher temperatures for extended periods, driving the reaction towards lactulose production, which is suitable for industrial lactulose production under harsh conditions.
研究领域:
酶工程
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工业生物技术
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生物化学
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分子生物学
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生物催化
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产品关联
DOI
PubMed
高影响因子
TALANTA
·
2021
·
IF 6.057
Pengfei Guan,Chengyi Xie,Lei Li,Xiangyu Fang,Fangling Wu,Jun Jack Hu,Keqi Tang
Carbohydrates are an indispensable part of early life evolution. The determination of their structures is a key step to analyze their critical roles in biological systems. A variation of composition , glycosidic linkage , and (or) configuration between carbohydrate isomers induces structure diversity and brings challenges for their structural determination. Ion mobility spectrometry (IMS), an emerging gas-phase ion separation technology, has been considered as a promising tool for performing carbohydrate structure elucidation . In this work, eight disaccharides were analyzed by trapped ion mobility spectrometry-mass spectrometry (TIMS-MS) in the negative ion mode as the complexed form of [M + X] - , where M = disaccharide, and X = Cl, Br, and I. As compared to the positive ion analysis of the selected disaccharide in a sodiated form, a reversal charge state provided the ability to eliminate or even reverse the collision cross section (CCS) difference between disaccharide isomers. By the combination of TIMS analysis and the calculation of density functional theory, the only observed two conformers of ions [lactulose + I] - may result from different adduction sites for an iodide anion. Based on the comparison of different halogen adducts, the [M + I] - ion form exhibited more powerful ability for isomeric disaccharide differentiation with an average resolution ( R P-P ) of 1.17, which results in a 34.5% improvement as compared to the corresponding chloride adducts. This result indicates that the use of negative charge states, especially the complexation of an iodide anion, could be a supplemental strategy to commonly used positive ion analysis for carbohydrate separation.
研究领域:
分析化学
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质谱
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碳水化合物化学
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离子迁移率光谱
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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）