JOURNAL OF BIOTECHNOLOGY
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2014
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IF 2.884
Chengli Hu,Na Wang,Weiwei Zhang,Sheng Zhang,Yanfa Meng,Xiaoqi Yu
The aim of this study was to improve the ability of Aspergillus terreus lipase to separate the racemic ketoprofen vinyl ester into individual enantiomers using hollow self-assembly alginate- graft -poly(ethylene glycol)/α-cyclodextrins (Alg- g -PEG/α-CD) spheres as enzyme immobilization carriers. The morphology and size of the Alg- g -PEG/α-CD particles were investigated by transmission electron microscopy (TEM) and were found to be nanoscale. To facilitate recycling, calcium alginate (CA) beads were developed to encapsulate Alg- g -PEG/α-CD particles, thereby producing Alg- g -PEG/α-CD/CA composite beads. The influence of buffer pH and enzyme concentration during immobilization was studied along with the biocatalyst's kinetic parameters. When the immobilized enzyme was under optimal conditions in the resolution reaction, maximal conversion (approximately 45.9%) and enantioselectivity (approximately 128.8) were obtained. The immobilized A. terreus lipase maintained excellent performance even after 20 reuses and retained nearly 100% of its original activity after 24 weeks of storage at 4 °C.
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RSC Advances
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2017
·Vol. 7
·期 3
·1504-1512
·
IF 3.108
Guiying Wu,Xin He,Yunjun Yan
Polyols are one of the dominant reactants in polyurethane (PU) synthesis. However, polyols from Sapium sebiferum oil prepared by epoxidation–hydroxylation have an inferiority of secondary alcohol groups and large non-functional branches. Their lower reactivity, which in turn limits the properties of the generated PU. In this study, the optimal reaction conditions for the synthesis of polyols with primary alcohol groups by lipase hydrolysis have been investigated by single factorial experiments and response surface methodology. The optimized conditions for lipase hydrolysis were identified as a molar ratio of 2.2 : 1, a reaction time of 11.2 h, and a temperature of 47.2 °C. The highest hydroxyl value of the obtained polyol with primary alcohol groups reached 211 mg KOH per g. Furthermore, a novel PU was successfully synthesized from the synthetic polyol and isophorone diisocyanate by an in situ polymerization method. The generated PU showed a glass transition temperature of 60.6 °C, an initial decomposition temperature of 307.2 °C, a tensile strength of 12.5 MPa, and a Young's modulus of 22.3 MPa. These good thermal and mechanical properties of the PU prepared from the modified polyol by lipase hydrolysis can be attributed to its greater number of chemical interactions and cross-linked networks.
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RENEWABLE ENERGY
·
2024
·
IF 9
Shuaibo Xia,Cai Shen,Jiale Lin,Maolin Tu,Chin-Ping Tan,Ling-Zhi Cheong
The absorption process of Aspergillus oryzae lipase (AOL) onto the surface of ZIF-8 was elucidated using molecular dynamic (MD) simulation. AOL are absorbed onto the surface of ZIF-8 via hydrogen bonding, electrostatic and van der Waals interaction with minimal changes to its native configurations. Unlike free AOL, AOL@ZIF-8 can maintain its structure in simulated methanol solutions. To verify the results from MD simulation, AOL was immobilized onto ZIF-8 (AOL@ZIF-8: immobilization efficiency of 64.71 % and a protein loading of 57.36 mg/g) and characterized using SEM, FTIR, and XRD. As compared to free AOL, AOL@ZIF-8 demonstrated higher transesterification activity with an activity recovery of 106.18 %. In agreement with MD simulations, AOL@ZIF-8 exhibited enhanced stability in wide range of pH and under presence of alcohol solution. AOL@ZIF-8 can be used to catalyze transesterification of used cooking oil for production of biodiesel (FAME content of 81.19 %).
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BIORESOURCE TECHNOLOGY
·
2024
·
IF 9.7
Lili Xu,Qingqing Zhao,Haibo Liu,Dankui Liao,Aixing Tang,Youyan Liu
Limonene dioxide (LDO) is essential for manufacturing bio-based polycarbonate and non-isocyanate polyurethanes. Herein, we report a strategy for the chemoenzymatic epoxidation of (R)-(+)-limonene to LDO with high selectivity using Rhizopus oryzae whole cells. The presence of sufficient excess acid in the system is essential, in addition to overcoming the hydrolysis of the intermediate product, 1,2-limonene oxide, to accomplish the double epoxidation of limonene. When using a high concentration of H 2 O 2 and trisodium citrate, the conditions were effectively established, even when Novozym 435 was substituted, which had previously been reported to be ineffective in achieving high-yield double epoxidation of limonene. The transfer of H 2 O 2 and peracids between the cell and solvent slowed production. The total amount of peracids generated remained constant, but their concentrations remained moderate, favoring the double epoxidation of limonene. An LDO yield of 93 % and no intermediate product, limonene oxide, were obtained under optimized conditions within 20 h.
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OPTICS AND LASER TECHNOLOGY
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2024
·
IF 4.6
Hongxin Zhang,Xuegang Li,Xue Zhou,Yanan Zhang,Yong Zhao
As a precursor to butyric acid and also a short-chain triglyceride, tributyrin plays an important role in repairing small intestinal villi, promoting the absorption and utilization of nutrients, and monitoring human health. The traditional carboxylation functionalization method of optical fiber sensors takes a long time and is complicated to operate. Therefore, we need a sensor with a functional period, high sensitivity, and the ability to quickly detect samples to achieve specific detection of tributyrin. In this paper, based on the chemical cross-linking method of polydopamine-maleic acid (PDA-MA), a novel fiber-optic microfluidic surface plasmon resonance (SPR) sensor was proposed to realize the detection of tributyrin. Compared with the traditional functionalization method, the fixation method of PDA-MA chemical cross-linking method not only shortens the functionalization time, but also increases the sensitivity of the sensor. Experimental results show that the sensitivity of the microfluidic sensor coated with PDA reaches 3392.7 nm/RIU, which is 1.75 times that of the uncoated sensor. The sensor has a sensitivity of 8.22 nm/mM in the range of 0.5–5 mM and a response time of only 8 min at the concentration of 1 mM. In addition, the sample detection error of the sensor is within 12 % in the range of 0.5–5 mM. The proposed sensor offers the advantages of low sample consumption (100 μL), high sensitivity, good selectivity, good repeatability, anti-interference ability, and label-free measurement. The sensor holds promising applications in food safety and health monitoring due to its superior performance.
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LWT-FOOD SCIENCE AND TECHNOLOGY
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2024
·
IF 6
Xi Cao,Miao Qiao,Dongjie Zuo,Sihan Lei,Yongjun Yuan
Structured triacylglycerols (STAGs) with medium-chain fatty acids (FAs) at sn -1,3 positions and long-chain FAs at the sn -2 position are known as medium-long-medium (MLM) type STAGs. They can not only provide energy immediately and control weight effectively, but may also provide essential or beneficial FAs to meet the human needs. In this study, MLM type STAGs were synthesized from lipase-catalyzed acidolysis of peony seed oil (PSO) with octanoic acid (OcA) and decanoic acid (DA) as medium-chain FAs in solvent-free systems. Optimal reaction conditions were 1:8 (PSO to OcA/DA), 40 °C and 24 h. The OcA content and DA content at sn -1,3 of two STAGs were 81.1% and 82.5%. The total essential FA (α-linolenic acid and linoleic acid) contents at sn -2 reached 61.5% and 57.2%, and long-chain unsaturated FA contents reached 93.3% and 87.4%. Infrared absorptions of two STAGs were weaker than those of PSO at 723 cm −1 [-(CH 2 ) n -rocking] and 3011 cm −1 [ = CH (cis) stretching]. The end melting temperature and maximum weight loss temperature of STAG rich in DA were higher than those of STAG rich in OcA. This study is conducive to the deep processing of PSO and provides a new and promising substrate for MLM type STAG synthesis.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2024
·
IF 5.7
Feina Gu,Ya Wen,Xinyu Hu,Huabin Liao,Chunfang He,David Julian McClements,Weichun Pan,Fuge Niu
Porous starch granules (PSGs) are promising biomaterials for the encapsulation, protection, and delivery of bioactive ingredients. In this study, a lipase treatment was first used to generate pores in native starch granules, and then α-amylase was used to enlarge these pores. Electron and fluorescence microscopy analysis showed that the lipase treatment exposed the starch molecules located below the lipid-rich regions on the starch granule surfaces, which increased the swelling of the granules in aqueous solutions. Moreover, lipase treatment caused the surrounding areas to become more loosely packed, which facilitated subsequent starch hydrolysis and the formation of large internal cavities. Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analyses provided further insights, these methods showed that the short-range order, long-range order, and thermal stability of the PSGs was enhanced by the sequential lipase-amylase modification. PSGs were highly resistant to amylase digestion and had strong adsorption capacity to hydrophobic and hydrophilic substances. This study shows that a combined lipase-amylase treatment can be used to fabricate PSGs, which may have health benefits due to their low digestibility and ability to encapsulate bioactive agents. These PSGs may therefore be suitable for application in the functional food, supplement, personal care, and pharmaceutical industries.
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Journal of Analysis and Testing
·
2024
·
IF 5.5
Zhang Hui,Chen Guilin,Zhang Yongli,Muema Felix Wambua,Ding Jun,Guo Mingquan
With the growing prevalence of diabetes and obesity worldwide, the role of α -glucosidase and lipase inhibitors has gained increasing concentration. Mulberry, a functional medicinal and edible plant, has been reported extensively in alleviating both diabetes and obesity. However, there is still a lack of refined research on its active ingredients and mechanisms. In our study, the inhibitory activities of mulberry leaf against α -glucosidase and pancreatic lipase reached 191.37 ± 14.46 and 775 ± 68.60 μg/mL, respectively. Meanwhile, it also promoted glucose consumption in the HepG2 cells model. Subsequently, four α -glucosidase ligands and four pancreatic lipase ligands were identified through bio-affinity ultrafiltration combined with liquid-chromatography-mass spectrometry (UF-HPLC–MS/MS). In vitro inhibition assays confirmed the inhibitory potential of these representative ligands. Molecular docking suggested that these possible ligands could be inserted into the active pocket of the target enzyme through multiple intermolecular forces. Our findings indicated that the polyphenols in mulberry leaves may contribute significantly to their hypoglycemic and hypolipidemic properties. Furthermore, our study provides valuable insights for the screening of active ingredients in other medicinal and edible plants, which could help in the development of new therapies for diabetes and obesity.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Ran Zhang,Lulu Xing,Xin Wang,Zuoyu Shan,Tianxin Wang,Ye Zhang,Wenjie Wang,Yuan Wang,Hao Wang
Inhibiting the activity of pancreatic lipase and reducing intestinal cholesterol absorption are potential strategies to combat obesity. This study investigated the mechanisms by which hawthorn ( Crataegus pinnatifida ) extract affects pancreatic lipase (PL) and disrupts cholesterol micelle formation. Enriched with bioactive compounds, hawthorn extract (HE) inhibited PL activity through reversible mixed inhibition, with a half-maximal inhibitory concentration (IC50) of 2.92 mg/mL. Infrared spectroscopy, circular dichroism and fluorescence quenching experiments demonstrated that HE binding to PL induces conformational changes in both tertiary and secondary structures. This interaction facilitated the transformation of β-turns to random coils and quenched the fluorescence of the protein through a static quenching mechanism. HPLC, immobilized enzymes and molecular docking studies collectively revealed that rutin, chlorogenic acid, and isoquercitrin in HE exhibited strong binding affinity with PL, serving as key components in inhibiting PL activity. Furthermore, HE increased the particle size of cholesterol micelles while decreasing their solubility, which makes it more difficult for lipases to function in the intestine. Overall, our study suggests that HE may serve as an effective pancreatic lipase inhibitor, presenting potential applications in the development of functional foods for obesity reduction and lipid-lowering.
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JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2024
·
IF 3.3
Buqing Wang,Yasen Wang,Xiaoman Zhou,Xiao-Dong Gao,Morihisa Fujita,Zijie Li
BACKGROUND Acidic lipases with high catalytic activities under acidic conditions have important application values in the food, feed and pharmaceutical industries. However, the availability of acidic lipases is still the main obstacle to their industrial applications. Although a novel acidic lipase Rasamsonia emersonii (LIPR) was heterologously expressed in Escherichia coli , the expression level was unsatisfactory. RESULTS To achieve the high-efficiency expression and secretion of LIPR in Pichia pastoris GS115, the combinatorial optimization strategy was adopted including gene codon preference, signal peptide, molecular chaperone co-expression and disruption of vacuolar sorting receptor VPS10 . The activity of the combinatorial optimization engineered strain in a shake flask reached 1480 U mL −1 , which was 8.13 times greater than the P. pastoris GS115 parental strain. After high-density fermentation in a 5-L bioreactor, the highest enzyme activity reached as high as 11 820 U mL −1 . LIPR showed the highest activity at 40 °C and pH 4.0 in the presence of Ca 2+ ion. LIPR exhibited strong tolerance to methanol, indicating its potential application in biodiesel biosynthesis. Moreover, the gastrointestinal digestion simulation results demonstrated that LIPR was tolerant to pepsin and trypsin, but its activity was inhibited by sodium taurodeoxycholate. CONCLUSION This study provided an effective approach for the high expression of acidic lipase LIPR. LIPR was more appropriate for lipid digestion in the stomach than in intestine according to the gastrointestinal digestion simulation results. © 2024 Society of Chemical Industry.
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MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Linlin Chen,Songyao Wu,Wei Li,Ming Zhang,Xiao Yu,Jiaqi Song,Dong Liang,Jiaxin Zhang
Organophosphorus pesticides (OPs) are one of the most widely used pesticides in agricultural production, which can cause accumulation of acetylcholine, overstimulation of synaptic receptors, and ultimately lead to neurological damage. Based on the activity of hybrid lipase to catalyze the hydrolysis of OPs to produce P-NP and the inhibition of its ability to hydrolyze P-NPP by OPs, a dual assay system has been developed, which enables the detection of OPs with high sensitivity and low cost. Meanwhile, a hybridization lipase (BCL@Zn-hNF) with high catalytic activity and large surface area was prepared, and a cascaded sensor simulating peroxidase activity (BCL@Zn-hNF/AuNPs/Au) was established and used for electrochemical biosensor detection of OPs residues. In addition, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) results show that BCL@Zn-hNF consists of interlaced lamellar structures. Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and particle size analysis confirm the presence of phosphates. The hybridization process did not significantly affect its crystal morphology with good stability and dispersion. These results confirm the successful preparation of BCL@Zn-hNF. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) verified that adding BCL@Zn-hNF increased the sensor's catalytic rate. The sensor exhibited good sensitivity (5.182 × 10 8 A M −1 cm −2 ), a wide linear range (3.80 × 10 −8 –4.56 × 10 −5 M), and a low detection limit (1.03 × 10 −9 M) for the indirect detection of OPs compared with the direct detection. Meanwhile, it has good reproducibility, stability, and immunity to interference in the detection of OPs, and good recovery for the detection of MP residues in real samples.
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BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
·
2015
·
IF 2.297
Xuping Wang,Qingyun Tang,Grzegorz Maria Popowicz,Bo Yang,Yonghua Wang
More and more industrial chemistry reactions rely on green technologies. Enzymes are finding increasing use in diverse chemical processes. Epoxidized vegetable oils have recently found applications as plasticizers and additives for PVC production. We report here an unusual activity of the Malassezia globosa lipase (SMG1) that is able to catalyze epoxidation of alkenes. SMG1 catalyzes formation of peroxides from long chain carboxylic acids that subsequently react with double bonds of alkenes to produce epoxides. The SMG1 is selective towards carboxylic acids and active also as a mutant lacking hydrolase activity. Moreover we present previously unobserved mechanism of catalysis that does not rely on acyl–substrate complex nor tetrahedral intermediate. Since SMG1 lipase is activated by allosteric change upon binding to the lipophilic–hydrophilic phase interface we reason that it can be used to drive the epoxidation in the lipophilic phase exclusively.
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危险品化学品经营许可证（带存储）