Biomineralization of enzymes inside rigid metal-organic frameworks (MOFs) is appealing due to its biocompatibility and simplicity. However, this strategy has hitherto been limited to microporous MOFs, leading to low apparent enzymatic activity. In this study, polysaccharide sodium alginate is introduced during the biomineralization of enzymes in zeolitic imidazolate frameworks (ZIFs) to competitively coordinate with metal ions, which endows the encapsulated enzyme with a 7-fold higher activity than that in microporous ZIFs.
View Article and Find Full Text PDFMicrobial biosynthesis has become the leading commercial approach for large-scale production of terpenoids, a valuable class of natural products. Enhancing terpenoid production, however, requires complex modifications on the host organism. Recently, a two-step isopentenol utilization (IU) pathway relying solely on ATP as the cofactor has been proposed as an alternative to the mevalonate (MVA) pathway, streamlining the synthesis of the common terpenoid precursors.
View Article and Find Full Text PDFThe quorum-sensing receptor SdiA is vital for regulating the desiccation tolerance of C. sakazakii, yet the specific mechanism remains elusive. Herein, transcriptomics and phenotypic analysis were employed to explore the response of C.
View Article and Find Full Text PDFSturgeon has a long lifespan and slow evolutionary rate due to their powerful endogenous antioxidant system. This work aimed to assess the in vitro and in vivo antioxidant activity of sturgeon extracts from both muscle and roe. The extraction process without enzyme hydrolysis is not only simple, but also can produce extracts with better free radicals scavenging abilities than enzymatic hydrolysates in both cellular and in vivo experiments.
View Article and Find Full Text PDFIn response to the environmental pollution caused by non-degradable and non-recyclable plastic packaging films (PPFs) and the resulting health concerns due to the migration of microplastics into food, the development of biodegradable food packaging films has gained great attention. Chitosan has been extensively utilized in the food industry owing to its abundant availability, exceptional biocompatibility, degradability, and antimicrobial properties. Chitosan-essential oil composite films (CEOs) represent a promising avenue to replace conventional PPFs.
View Article and Find Full Text PDFThe aim of this study was to investigate the effects of acetylation modification on the structural, interfacial and emulsifying properties of Millettia speciosa Champ polysaccharide (MSCP). Besides, the influence of acetylation modification on the encapsulation properties of polysaccharide-based emulsion was also explored. Results indicated that modification resulted in a prominent reduction in molecular weight of MSCP and the interfacial layer thickness formed by acetylated MSCP (AC-MSCP) was also decreased, but the adsorption rate and ability of AC-MSCP to reduce interfacial tension were improved.
View Article and Find Full Text PDFDihydroquercetin (DHQ), known for its varied physiological benefits, is widely used in the food, chemical, and pharmaceutical industries. However, the efficiency of the DHQ synthesis is significantly limited by the substantial accumulation of intermediates during DHQ biosynthesis. In this study, DHQ production was achieved by integrating genes from various organisms into the yeast chromosome for the expression of flavanone-3-hydroxylase (F3H), flavonoid-3'-hydroxylase, and cytochrome P450 reductase.
View Article and Find Full Text PDFIn this study, we used traditional laboratory methods, bioinformatics, and cellular models to screen novel ACE inhibitory (ACEI) peptides with strong ACEI activity, moderate absorption rates, and multiple targets from bovine colostrum immunoglobulin G (IgG). The purified fraction of the compound proteinase hydrolysate of IgG showed good ACEI activity. After nano-UPLC-MS/MS identification and analysis, eight peptides were synthesized and verified.
View Article and Find Full Text PDFAn iron-incorporated Zn-MOF catalyst Zn-bpydc·Fe was fabricated for the oxidative cleavage of -anethole to -anisaldehyde under facile conditions, under 1 atm of O. The Fe coordinated bipyridine serves as the catalytically active center inside the structural skeleton of Zn-MOFs. This work affords a new avenue for the mild oxidation of olefins.
View Article and Find Full Text PDFEnzymes achieve high catalytic activity with their elaborate arrangements of amino acid residues in confined optimized spaces. Nevertheless, when exposed to complicated environmental implementation scenarios, including high acidity, organic solvent and high ionic strength, enzymes exhibit low operational stability and poor activity. Here, we report a metal-organic frameworks (MOFs)-based artificial enzyme system via second coordination sphere engineering to achieve high hydrolytic activity under mild conditions.
View Article and Find Full Text PDFPesticide residues have raised considerable concern about environmental health and food safety. Despite a great advance in enzymatic sensors for pesticide detection, the intrinsic fragility of native enzyme and possible fake results due to single mode signal have hindered its wide application. Here, a novel dual-mode sensor is reported for organophosphorus pesticide detection by using metal-organic framework (MOF) nanozyme NH-CuBDC as sensing element.
View Article and Find Full Text PDFAppl Biochem Biotechnol
June 2024
The modulation of whole-cell activity presents a considerable challenge in biocatalysis. Conventional approaches to whole-cell catalysis, while having their strengths, often rely on complex and deliberate enzyme designs, which could result in difficulties in activity modulation and prolonged response times. Additionally, the activity of intracellular enzymes in whole-cell catalysis is influenced by temperature.
View Article and Find Full Text PDFBackground: Lactobacillus species in gut microbiota shows great promise in alleviation of metabolic diseases. However, little is known about the molecular mechanism of how Lactobacillus interacts with metabolites in circulation. Here, using high nucleoside intake to induce hyperuricemia in mice, we investigated the improvement in systemic urate metabolism by oral administration of L.
View Article and Find Full Text PDFWe report for the first time the usage of Millettia speciosa Champ cellulose (MSCC) and carboxymethylcellulose (MSCCMC) for the fabrication of 3D-network hydrogel as delivery system for probiotics. The structural features, swelling behavior and pH-responsiveness of MSCC-MSCCMC hydrogels and their encapsulation and controlled-release behavior for Lactobacillus paracasei BY2 (L. paracasei BY2) were mainly studied.
View Article and Find Full Text PDFImproving the activity of β-xylosidase at high temperature and organic solvents is important for the conversion of xylan, phytochemicals and some hydroxyl-containing substances to produce xylose and bioactive substances. In this study, a β-xylosidase R333H and an endoxylanase were simultaneously co-immobilized on the metal-organic framework UiO-66-NH. Compared with the single R333H immobilization system, the co-immobilization enhanced the activity of R333H at high temperature and high concentration of acetone, and the relative activities at 95 °C and 50% acetone solution were >95%.
View Article and Find Full Text PDFIn the study, monodispersed silver nanoparticles (AgNPs) with an average diameter of 9.57 nm were efficiently and controllably biosynthesized by a reductase from DO7 only in the presence of β-NADPH and polyvinyl pyrrolidone (PVP). The reductase responsible for AgNP formation in DO7 was further confirmed as 1,4-α-glucosidase.
View Article and Find Full Text PDFThe accumulated antibiotics in the aquatic environment pose great threat to human and ecological health, boosting the development of porous materials for antibiotic removal. Mesoporous metal-organic frameworks (MOFs) have shown great promise in adsorption, which, however, usually need supramolecular design or cooperative template strategy for synthesis. Here we report the successful construction of mesoporous zirconium based metal-organic frameworks (Zr-MOFs) via a simple solvent-dependent strategy.
View Article and Find Full Text PDFAn acid polysaccharide, named HP, was produced by endophytic Penicillium javanicum MSC-R1 isolated from southern medicine Millettia speciosa Champ. The molecular weight of HP was 37.8 kDa and consisted of Ara f, Galр, Glcр, Manр, and GlcрA with a molar ratio of 1.
View Article and Find Full Text PDFProbiotics Antimicrob Proteins
February 2024
In this study, five strains of lactic acid bacteria (LAB) with excellent cholesterol-lowering ability were screened from fermented foods. The gastrointestinal stress resistance, intestinal adhesion, and bacteriostasis abilities were evaluated to obtain the best LAB. And then, high-cholesterol HepG2 cell model was further prepared to explore the cholesterol-lowering mechanism of the LAB.
View Article and Find Full Text PDFAmmonia lyases have great application potential in food and pharmaceuticals owing to their unique ammonia addition reaction and atom economy. A novel methylaspartate ammonia-lyase, EcMAL, from E. coli O157:H7 showed high catalytic activity.
View Article and Find Full Text PDFIn this study, a natural antioxidant emulsifier, Millettia speciosa Champ polysaccharide conjugates (MSC-PC), was used for fabricating oil-in-water emulsion, and the influences of MSC-PC on β-carotene stability and bioaccessibility were studied. Results suggested that MSC-PC stabilized emulsion exhibited excellent resistance to a wide range of salt levels (0-500 mM of Na), thermal treatments (50-90 °C) and pH values (3.0-11.
View Article and Find Full Text PDFBioresour Bioprocess
July 2022
Background: The combination of metal-catalyzed reactions and enzyme catalysis has been an essential tool for synthesizing chiral pharmaceutical intermediates in the field of drug synthesis. Metal catalysis commonly enables the highly efficient synthesis of molecular scaffolds under harsh organic conditions, whereas enzymes usually catalyze reactions in mild aqueous medium to obtain high selectivity. Since the incompatibility between metal and enzyme catalysis, there are limitations on the compatibility of reaction conditions that must be overcome.
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