Publications by authors named "Pengmei Lv"

Using an engineered to produce lipase and can easily achieve high-level expression. The investigation of biochemical processes during lipase fermentation, approached from a metabolomics perspective, will yield novel insights into the efficient secretion of recombinant proteins. In this study, the lipase batch fermentation was carried out first with enzyme activity of 36.

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The enzymatic production of biodiesel from waste cooking oils (WCOs) offers a green and sustainable solution for the liquid fuel manufacture as well as waste resource recovery. In present study, liquid lipase was used to simplify the catalysis process, thereby reducing biodiesel production costs. An engineered Escherichia coli expressing Geobacillus thermocatenulatus lipase 2 (GTL2) was screened at an enzyme activity of 6.

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The construction of methanol-resistant lipases with high catalytic activity is world-shattering for biodiesel production. A semi-rational method has been constructed to enhance the properties of Rhizomucor miehei lipase with propeptide (ProRML) by introducing N-glycosylation sites in the Loop structure. The enzyme activities of the mutants N288 (1448.

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Exploiting highly active and methanol-resistant lipase is of great significance for biodiesel production. A semi-rational directed evolution method combined with N-glycosylation is reported, and all mutants exhibiting higher catalytic activity and methanol tolerance than the wild type (WT). Mutant N267 retained 64% activity after incubation in 50% methanol for 8 h, which was 48% greater than that of WT.

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Article Synopsis
  • Liquid lipases, like Rhizomucor miehei lipase (RML), are essential for producing biodiesel, and improving their catalytic activity and methanol tolerance is crucial for industrial applications.
  • A study optimized the lipase by using semi-rational design, leading to significant increases in enzyme activity for several mutants, with one mutant (N218) showing a remarkable 66.81-fold increase.
  • The study concluded that modifying the α-helix structure through N-glycosylation enhances the enzyme's efficiency and suitability for large-scale biodiesel production.
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The propeptide is a short sequence that facilitates protein folding. In this study, four highly active Rhizomucor miehei lipase (RML) mutants were obtained through saturation mutagenesis at three propeptide positions: Ser8, Pro35, and Pro47. The enzyme activities of mutants P35 N, P47 G, P47 N, and S8E/P35S/P47A observed at 40 °C, and pH 8.

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Due to its simple, less by-product and environment friendly properties, enzymatic transesterification of oil with short-chain alcohol to biodiesel, fatty acid methyl esters (FAMEs) is considered to be a promising way of green production and has attracted much attention. In this study, FAMEs were synthesized by an enzymatic method with recombinant lipase as catalysts. A thermophilic Bacillus thermocatenulatus lipase 2 (BTL2) was overexpressed in Escherichia coli BL21(DE3) through relative and quantitative analysis using real-time quantitative PCR.

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To develop an economically feasible fermentation process, this study designed a novel bioprocess based on the co-culture of engineered Bacillus subtilis and Escherichia coli for the co-production of extracellular D-psicose and intracellular lipase. After optimizing the co-culture bioprocess, 11.70 g/L of D-psicose along with 16.

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Crude glycerol, a by-product of biodiesel production, was employed as the carbon source to produce lipase using . Under identical fermentation conditions, cell growth and lipase activity were improved using crude glycerol instead of pure glycerol. The impacts of crude glycerol impurities (methyl ester, grease, glycerol, methanol, and metal ions Na, Ca, and Fe) on lipase production were investigated.

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Long-chain fatty acids are widely used in food and chemical industries, and the enzymatic preparation of fatty acids is considered an environmentally friendly process. In the present study, long-chain fatty acids were prepared by the enzymatic hydrolysis of rapeseed oil with a genetically engineered lipase. Because thermophilic lipase has strong stability at higher temperatures, it was more suitable for the industrial production of long-chain fatty acids.

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Biodiesel biosynthesis with enzymatic transesterification is considered green, sustainable, and environmentally friendly method. Lipase from Burkholderia cepacia G63 has excellent catalytic properties in biodiesel production. Lipase chaperones promote secretion and folding of enzymes, thereby enhancing enzymatic activity.

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d-Psicose, as important rare sugar and epimer of d-fructose on the C-3 position, displays unique health benefits and physiological functions in various fields. The production of d-psicose is currently obtained via enzymatic bioconversion, mostly with of d-tagatose 3-epimerase. In the present study, the isomerization of d-fructose into d-psicose was achieved by constructing engineered food-grade Bacillus subtilis through fermentation.

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In this article, a novel nano-rod-shaped SAPO-11 molecular sieve (SAPO-11-A-F) with a thickness of 100 nm was successfully fabricated by the seed-induced steam-assisted method using the cationic surfactant cetyltrimethylammonium bromide (CTAB) as a mesoporous template and a nonionic copolymer poly(ethylene oxide)--poly(propylene oxide)--poly(ethylene oxide), F, as the crystal growth inhibitor. The fabricated nano-rod-shaped SAPO-11-A-F possessed nanocrystalline size, a hierarchical porous structure, and enhanced acidic sites. The added CTAB was mainly used to enhance the mesoporous structure and acid, and F acted as a grain growth inhibitor.

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In this work, porous cross-linked enzyme aggregates (p-CLEAs) were synthesized by the co-precipitation method using CaCO microparticles as templates. The preparation procedure involved the immobilization of crude lipase as CLEAs precipitation with ammonium sulfate and entrapping these lipase molecules into the CaCO templates, followed by DTT (dithiothreitol)-induced assembly of lipase molecules to form lipase microparticles (lipase molecules were assembled into microparticles internally using disulfide bonds within the lipase molecules as the molecular linkers and stimulated by dithiothreitol); finally, the removal of CaCO templates was performed by EDTA to form pores in CLEAs. The scanning electron microscopy analysis of p-CLEAs showed a porous structure.

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Sanger's reaction, which was originally developed for amino acid detection, was utilized for enzyme immobilization. The newly synthesized polymer support, which was called polymer NO-4-fluorostyrene-divinylbenzene (pNFD), was embedded with a Sanger's reagent-like functional group for immobilizing enzymes covalently under mild reaction conditions. Using Burkholderia cepacia lipase (BCL) as the target enzyme, the immobilization efficiency and activity of pNFD-BCL reached as high as 1.

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Elephant grass might be a potential source of fine chemical precursors and bioenergy. In the present study, we investigated the dynamics of hydrolysis of elephant grass. Three models were used to fit the hydrolysis rate constants-flat, spherical, and cylindrical models.

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The methanogenic propionate degradation consortia were enriched in a propionate-fed semi-continuous bioreactor. The microbial community shift with depth, the microbial network and its correlation with metabolic pathway were also investigated. The results demonstrated that the maximum organic loading rate (OLR) of the reactor was 2.

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Directed evolution has been proved an effective way to improve the stability of proteins, but high throughput screening assays for directed evolution with simultaneous improvement of two or more properties are still rare. In this study, we aimed to establish a membrane-blot assay for use in the high-throughput screening of Rhizomucor miehei lipases (RMLs). With the assistance of the membrane-blot screening assay, a mutant E47K named G10 that showed improved thermal stability was detected in the first round of error-prone PCR.

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For high caloricity and stability in bio-aviation fuels, a certain content of aromatic hydrocarbons (AHCs, 8-25 wt%) is crucial. Fatty acids, obtained from waste or inedible oils, are a renewable and economic feedstock for AHC production. Considerable amounts of AHCs, up to 64.

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Bimetallic nanoparticles with core-shell structures usually display enhanced catalytic properties due to the lattice strain created between the core and shell regions. In this study, we demonstrate the application of bimetallic Au-Pd nanoparticles with an Au core and a thin Pd shell as cathode catalysts in microbial fuel cells, which represent a promising technology for wastewater treatment, while directly generating electrical energy. In specific, in comparison with the hollow structured Pt nanoparticles, a benchmark for the electrocatalysis, the bimetallic core-shell Au-Pd nanoparticles are found to have superior activity and stability for oxygen reduction reaction in a neutral condition due to the strong electronic interaction and lattice strain effect between the Au core and the Pd shell domains.

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A large number of propeptide regions from various proteins have been identified which function as intramolecular chaperones and assist the folding of the respective functional domains. The same polypeptide can fold into an altered conformation because of a mutated intramolecular chaperone and can maintain the "memory" of the folding process (new physicochemical properties). Two new kinds of Rhizomucor miehei lipase (RML) were constructed by replacing its propeptide region with that from either Rhizopus chinensis lipase (RCL) or Rhizopus oryzae lipase (ROL).

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Rhizo mucor miehei lipase (RML) is an industrially important enzyme, but its application is limited due to its high cost. In this study, a series of measures such as codon optimization, propeptide addition, combined use of GAP and AOX1 promoters, and optimization of culture conditions were employed to increase the expression of RML. Three transformants of the constitutive-inducible combined Pichia pastoris strains were generated by transforming the pGAPZαA-rml vector into the pPIC9K-rml/GS115 strain, which resulted in high-expression yields of RML.

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