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学者姓名：许鑫琦
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Abstract ：
A large quantity of orange peel waste (OPW) is generated per year, yet effective biorefinery methods are lacking. In this study, Trichosporonoides oedocephalis ATCC 16958 was employed for hydrolyzing OPW to produce soluble sugars. Glycosyl hydrolases from Paenibacillussp.LLZ1 which can hydrolyze cellulose and hemicellulose were mined and characterized, with the highest beta-mannanase activity of 39.1 U/mg at pH 6.0 and 50 degree celsius. The enzyme was overexpressed in T. oedocephalis and the sugar production was enhanced by 16 %. The accumulated sugar contains 57 % value-added mannooligosaccharides by the hydrolysis of mannans. The process was intensified by a pretreatment combining H2O2 submergence and steam explosion to remove potential inhibitors. The mannooligosaccharides yield of 6.5 g/L was achieved in flask conversion and increased to 9.7 g/L in a 5-L fermenter. This study improved the effectiveness of orange peel waste processing, and provided a hydrolysis-based methodology for the utilization of fruit wastes.
Keyword ：
beta-mannanase beta-mannanase Mannooligosaccharides Mannooligosaccharides Orange peel waste Orange peel waste Pretreatment Pretreatment Trichosporonoides oedocephalis Trichosporonoides oedocephalis
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| GB/T 7714 | Zhou, Taotao , Ju, Xin , Yan, Lishi et al. Production of mannooligosaccharides from orange peel waste with β-mannanase expressed in Trichosporonoides oedocephalis [J]. | BIORESOURCE TECHNOLOGY , 2024 , 395 . |
| MLA | Zhou, Taotao et al. "Production of mannooligosaccharides from orange peel waste with β-mannanase expressed in Trichosporonoides oedocephalis" . | BIORESOURCE TECHNOLOGY 395 (2024) . |
| APA | Zhou, Taotao , Ju, Xin , Yan, Lishi , Fang, Ruiqi , Xu, Xinqi , Li, Liangzhi . Production of mannooligosaccharides from orange peel waste with β-mannanase expressed in Trichosporonoides oedocephalis . | BIORESOURCE TECHNOLOGY , 2024 , 395 . |
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Norepinephrine, a kind of beta-adrenergic receptor agonist, is commonly used for treating shocks and hypotension caused by a variety of symptoms. The development of a straightforward, efficient and environmentally friendly biocatalytic route for manufacturing norepinephrine remains a challenge. Here, we designed and realized an artificial biocatalytic cascade to access norepinephrine starting from 3, 4-dihydroxybenzaldehyde and L-threonine mediated by a tailored-made L-threonine transaldolase PsLTTA-Mu1 and a newly screened tyrosine decarboxylase ErTDC. To overcome the imbalance of multi-enzymes in a single cell, engineering of PsLTTA for improved activity and fine-tuning expression mode of multi-enzymes in single E.coli cells were combined, leading to a robust whole cell biocatalyst ES07 that could produce 100 mM norepinephrine with 99% conversion, delivering a highest time-space yield (3.38 g/L/h) ever reported. To summarized, the current study proposed an effective biocatalytic approach for the synthesis of norepinephrine from low-cost substrates, paving the way for industrial applications of enzymatic norepinephrine production.
Keyword ：
Biocatalytic cascade Biocatalytic cascade L-threonine transaldolase L-threonine transaldolase Tyrosine decarboxylase Tyrosine decarboxylase
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| GB/T 7714 | Xu, Lian , Shen, Jun-Jiang , Wu, Ming et al. An artificial biocatalytic cascade for efficient synthesis of norepinephrine by combination of engineered L-threonine transaldolase with multi-enzyme expression fine-tuning [J]. | INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES , 2024 , 265 . |
| MLA | Xu, Lian et al. "An artificial biocatalytic cascade for efficient synthesis of norepinephrine by combination of engineered L-threonine transaldolase with multi-enzyme expression fine-tuning" . | INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES 265 (2024) . |
| APA | Xu, Lian , Shen, Jun-Jiang , Wu, Ming , Su, Bing-Mei , Xu, Xin-Qi , Lin, Juan . An artificial biocatalytic cascade for efficient synthesis of norepinephrine by combination of engineered L-threonine transaldolase with multi-enzyme expression fine-tuning . | INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES , 2024 , 265 . |
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Hydroxytyrosol, a naturally occurring compound with antioxidant and antiviral activity, is widely applied in the cosmetic, food, and nutraceutical industries. The development of a biocatalytic approach for producing hydroxytyrosol from simple and readily accessible substrates remains a challenge. Here, we designed and implemented an effective biocatalytic cascade to obtain hydroxytyrosol from 3,4-dihydroxybenzaldehyde and l-threonine via a four-step enzymatic cascade composed of seven enzymes. To prevent cross-reactions and protein expression burden caused by multiple enzymes expressed in a single cell, the designed enzymatic cascade was divided into two modules and catalyzed in a stepwise manner. The first module (FM) assisted the assembly of 3,4-dihydroxybenzaldehyde and l-threonine into (2S,3R)-2-amino-3-(3,4-dihydroxyphenyl)-3-hydroxypropanoic acid, and the second module (SM) entailed converting (2S,3R)-2-amino-3-(3,4-dihydroxyphenyl)-3-hydroxypropanoic acid into hydroxytyrosol. Each module was cloned into Escherichia coli BL21 (DE3) and engineered in parallel by fine-tuning enzyme expression, resulting in two engineered whole-cell catalyst modules, BL21(FM01) and BL21(SM13), capable of converting 30 mM 3,4-dihydroxybenzaldehyde to 28.7 mM hydroxytyrosol with a high space-time yield (0.88 g/L/h). To summarize, the current study proposes a simple and effective approach for biosynthesizing hydroxytyrosol from low-cost substrates and thus has great potential for industrial applications.
Keyword ：
Biocatalytic cascade Biocatalytic cascade hydroxytyrosol hydroxytyrosol stepwisecatalysis stepwisecatalysis
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| GB/T 7714 | Liu, Wen-Kai , Su, Bing-Mei , Xu, Xin-Qi et al. Multienzymatic Cascade for Synthesis of Hydroxytyrosol via Two-Stage Biocatalysis [J]. | JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY , 2024 , 72 (27) : 15293-15300 . |
| MLA | Liu, Wen-Kai et al. "Multienzymatic Cascade for Synthesis of Hydroxytyrosol via Two-Stage Biocatalysis" . | JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 72 . 27 (2024) : 15293-15300 . |
| APA | Liu, Wen-Kai , Su, Bing-Mei , Xu, Xin-Qi , Xu, Lian , Lin, Juan . Multienzymatic Cascade for Synthesis of Hydroxytyrosol via Two-Stage Biocatalysis . | JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY , 2024 , 72 (27) , 15293-15300 . |
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The synthesis of steroids is challenging through multistep steroidal core modifications with high site-selectivity and productivity. In this work, a novel enzymatic cascade system was constructed for synthesis of testolactone by specific C17 lactonization/Δ1-dehydrogenation from inexpensive androstenedione using an engineered polycyclic ketone monooxygenase (PockeMO) and an appropriate 3-ketosteroid-Δ1-dehydrogenase (ReKstD). The focused saturation mutagenesis in the substrate binding pocket was implemented for evolution of PockeMO to eliminate the bottleneck effect. A best mutant MU3 (I225L/L226V/L532Y) was obtained with 20-fold higher specific activity compared to PockeMO. The catalytic efficiency (kcat/Km) of MU3 was 171-fold higher and the substrate scope shifted to polycyclic ketones. Molecular dynamic simulations suggested that the activity was improved by stabilization of the pre-lactonization state and generation of productive orientation of 4-AD mediated by distal L532Y mutation. Based on that, the three genes, MU3, ReKstD and a ketoreductase for NADPH regeneration, were rationally integrated in one cell via expression fine-tuning to form the efficient single cell catalyst E. coli S9. The single whole-cell biocatalytic process was scaled up and could generate 9.0 g/L testolactone with the high space time yield of 1 g/L/h without steroidal by-product, indicating the potential for site-specific and one-pot synthesis of steroid. © 2024
Keyword ：
Biosynthesis Biosynthesis Cell engineering Cell engineering Cytology Cytology Escherichia coli Escherichia coli Gene expression Gene expression Ketones Ketones Molecular dynamics Molecular dynamics Molecular orientation Molecular orientation
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| GB/T 7714 | Xu, Xinqi , Zhong, Jinchang , Su, Bingmei et al. Single-cell enzymatic cascade synthesis of testolactone enabled by engineering of polycyclic ketone monooxygenase and multi-gene expression fine-tuning [J]. | International Journal of Biological Macromolecules , 2024 , 275 . |
| MLA | Xu, Xinqi et al. "Single-cell enzymatic cascade synthesis of testolactone enabled by engineering of polycyclic ketone monooxygenase and multi-gene expression fine-tuning" . | International Journal of Biological Macromolecules 275 (2024) . |
| APA | Xu, Xinqi , Zhong, Jinchang , Su, Bingmei , Xu, Lian , Hong, Xiaokun , Lin, Juan . Single-cell enzymatic cascade synthesis of testolactone enabled by engineering of polycyclic ketone monooxygenase and multi-gene expression fine-tuning . | International Journal of Biological Macromolecules , 2024 , 275 . |
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S-omeprazole and R-rabeprazole are important proton pump inhibitors (PPIs) used for treating peptic disorders. They can be biosynthesized from the corresponding sulfide catalyzed by Baeyer-Villiger monooxygenases (BVMOs). During the development of BVMOs for target sulfoxide preparation, stereoselectivity and over- oxidation degree are important factors considered most. In the present study, LnPAMO-Mu15 designed previously and TtPAMO from Thermothelomyces thermophilus showed high (S)- and (R)-configuration stereoselectivity respectively towards thioethers. TtPAMO was found to be capable of oxidating omeprazole sulfide (OPS) and rabeprazole sulfide (RPS) into R-omeprazole and R-rabeprazole respectively. However, the overoxidation issue existed and limited the application of TtPAMO in the biosynthesis of sulfoxides. The structural mechanisms for adverse stereoselectivity between LnPAMO-Mu15 and TtPAMO towards OPS and the overoxidation of OPS by TtPAMO were revealed, based on which, TtPAMO was rationally designed focused on the flexibility of loops near catalytic sites. The variant TtPAMO-S482Y was screened out with lowest overoxidation degree towards OPS and RPS due to the decreased flexibility of catalytic center than TtPAMO. The success in this study not only proved the rationality of the overoxidation mechanism proposed in this study but also provided hints for the development of BVMOs towards thioether substrate for corresponding sulfoxide preparation.
Keyword ：
Baeyer-Villiger monooxygenase Baeyer-Villiger monooxygenase Flexibility Flexibility Overoxidation Overoxidation R-rabeprazole R-rabeprazole S-omeprazole S-omeprazole Stereoselectivity Stereoselectivity
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| GB/T 7714 | Su, Bingmei , Xu, Fahui , Zhong, Jinchang et al. Rational design on loop regions for precisely regulating flexibility of catalytic center to mitigate overoxidation of prazole sulfides by Baeyer-Villiger monooxygenase [J]. | BIOORGANIC CHEMISTRY , 2024 , 151 . |
| MLA | Su, Bingmei et al. "Rational design on loop regions for precisely regulating flexibility of catalytic center to mitigate overoxidation of prazole sulfides by Baeyer-Villiger monooxygenase" . | BIOORGANIC CHEMISTRY 151 (2024) . |
| APA | Su, Bingmei , Xu, Fahui , Zhong, Jinchang , Xu, Xinqi , Lin, Juan . Rational design on loop regions for precisely regulating flexibility of catalytic center to mitigate overoxidation of prazole sulfides by Baeyer-Villiger monooxygenase . | BIOORGANIC CHEMISTRY , 2024 , 151 . |
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Esomeprazole is the most popular proton pump inhibitor for treating gastroesophageal reflux disease. Previously, a phenylacetone monooxygenase mutant LnPAMOmu15 (LM15) was obtained by protein engineering for asymmetric synthesis of esomeprazole using pyrmetazole as substrate. To scale up the whole cell asymmetric synthesis of esomeprazole and reduce the cost, in this work, an Escherichia coli whole-cell catalyst harboring LM15 and formate dehydrogenase from Burkholderia stabilis 15516 (BstFDH) were constructed through optimized gene assembly patterns. CRISPR/Cas9 mediated insertion of Ptrc promoter in genome was done to enhance the expression of key genes to increase the cellular NADP supply in the whole cell catalyst, by which the amount of externally added NADP+ for the asymmetric synthesis of esomeprazole decreased to 0.05 mM from 0.3 mM for reducing the cost. After the optimization of reaction conditions in the reactor, the scalable synthesis of esomeprazole was performed using the efficient LM15-BstFDH whole-cell as catalyst, which showed the highest reported space-time yield of 3.28 g/L/h with 50 mM of pyrmetazole loading. Isolation procedure was conducted to obtain esomeprazole sodium of 99.55 % purity and > 99.9 % ee with 90.1 % isolation yield. This work provides the basis for production of enantio-pure esomeprazole via cost-effective whole cell biocatalysis. © 2024
Keyword ：
Asymmetric sulfoxidation Asymmetric sulfoxidation Cofactor engineering Cofactor engineering CRISPR/Cas9 CRISPR/Cas9 Esomeprazole Esomeprazole Whole-cell catalysis Whole-cell catalysis
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| GB/T 7714 | Xu, X. , Meng, Y. , Su, B. et al. Development of whole cell biocatalytic system for asymmetric synthesis of esomeprazole with enhancing coenzyme biosynthesis pathway [J]. | Enzyme and Microbial Technology , 2024 , 179 . |
| MLA | Xu, X. et al. "Development of whole cell biocatalytic system for asymmetric synthesis of esomeprazole with enhancing coenzyme biosynthesis pathway" . | Enzyme and Microbial Technology 179 (2024) . |
| APA | Xu, X. , Meng, Y. , Su, B. , Lin, J. . Development of whole cell biocatalytic system for asymmetric synthesis of esomeprazole with enhancing coenzyme biosynthesis pathway . | Enzyme and Microbial Technology , 2024 , 179 . |
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Dehydroepiandrosterone (DHEA) is an important neurosteroid hormone to keep human hormonal balance and reproductive health. However, DHEA was always produced with impurities either by chemical or biological method and required high-cost purification before the medical use. To address this issue, a novel chemo-enzymatic process was proposed and implemented to produce DHEA. An acetoxylated derivate of 4-androstene-3,17-dione (4-AD) was generated by chemical reaction and converted into DHEA by an enzyme cascade reaction combining a hydrolysis reaction with a reduction reaction. The hydrolysis reaction was catalyzed by a com-mercial esterase Z03 while the reduction reaction was catalyzed by E. coli cells co-expressing a 3 beta-hydroxysteroid dehydrogenase SfSDR and a glucose dehydrogenase BtGDH. After the condition optimization, DHEA was syn-thesized at a 100 mL scale under 100 mM of substrate loading and purified as white powder with the highest space-time yield (4.80 g/L/h) and purity (99 %) in the biosynthesis of DHEA. The successful attempt in this study provides a new approach for green synthesis of highly purified DHEA in the pharmaceutical industry.
Keyword ：
3?-hydroxysteroid dehydrogenase 3?-hydroxysteroid dehydrogenase Chemoenzymatic process Chemoenzymatic process Dehydroepiandrosterone Dehydroepiandrosterone Enzyme cascade Enzyme cascade Hydrolysis Hydrolysis
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| GB/T 7714 | Su, Bing-Mei , Shi, Yi-Bing , Lin, Wei et al. A chemoenzymatic process for preparation of highly purified dehydroepiandrosterone in high space-time yield [J]. | BIOORGANIC CHEMISTRY , 2023 , 133 . |
| MLA | Su, Bing-Mei et al. "A chemoenzymatic process for preparation of highly purified dehydroepiandrosterone in high space-time yield" . | BIOORGANIC CHEMISTRY 133 (2023) . |
| APA | Su, Bing-Mei , Shi, Yi-Bing , Lin, Wei , Xu, Lian , Xu, Xin-Qi , Lin, Juan . A chemoenzymatic process for preparation of highly purified dehydroepiandrosterone in high space-time yield . | BIOORGANIC CHEMISTRY , 2023 , 133 . |
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Monascus sp. is an important food microbial resource with the production of cholesterol-lowering agent lovastatin and other healthy metabolites. However, the mycotoxin citrinin naturally produced by Monascus sp. and the insufficient productivity of lovastatin limit its large-scale use in food industry. The aim of this paper is to modify a lovastatin-producing strain Monascus pilosus GN-01 through metabolic engineering to obtain a citrinin-free M. pilosus strain with higher yield of lovastatin. The citrinin synthesis regulator gene ctnR was firstly disrupted to obtain GN-02 without citrinin production. Based on that, the lovastatin biosynthesis genes (mokC, mokD, mokE, mokF, mokH, mokI, and LaeA) were, respectively, overexpressed, and pigment-regulatory gene (pigR) was knocked out to improve lovastatin production. The results indicated ctnR inactivation effectively disrupted the citrinin release by M. pilosus GN-01. The overexpression of lovastatin biosynthesis genes and pigR knockout could lead higher contents of lovastatin, of which pigR knockout strain achieved 76.60% increase in the yield of lovastatin compared to GN-02. These studies suggest that such multiplex metabolic pathway engineering in M. pilosus GN-01 is promising for high lovastatin production by a safe strain for application in Monascus-related food.
Keyword ：
Gene knockout Gene knockout Gene overexpression Gene overexpression Lovastatin Lovastatin Monascus pilosus Monascus pilosus
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| GB/T 7714 | Hong, Xiaokun , Guo, Tianlong , Xu, Xinqi et al. Multiplex metabolic pathway engineering of Monascus pilosus enhances lovastatin production [J]. | APPLIED MICROBIOLOGY AND BIOTECHNOLOGY , 2023 , 107 (21) : 6541-6552 . |
| MLA | Hong, Xiaokun et al. "Multiplex metabolic pathway engineering of Monascus pilosus enhances lovastatin production" . | APPLIED MICROBIOLOGY AND BIOTECHNOLOGY 107 . 21 (2023) : 6541-6552 . |
| APA | Hong, Xiaokun , Guo, Tianlong , Xu, Xinqi , Lin, Juan . Multiplex metabolic pathway engineering of Monascus pilosus enhances lovastatin production . | APPLIED MICROBIOLOGY AND BIOTECHNOLOGY , 2023 , 107 (21) , 6541-6552 . |
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Laccase is an efficient biocatalyst for oxidative polymerization of organic substrates. However, cost of enzyme preparation, low stability and residual protein diminish the efficiency of laccase mediated polymerization. In this work, a series of silicon dioxide coated ferroferric oxide magnetic nanoparticles were modified by different functional groups including gamma-methacryloxypropyltrimethoxy, succinic anhydride, glutaraldehyde and poly-ethylene imine. Infrared spectra indicated the magnetic carriers have been successfully modified. Vibrating sample magnetometer (VSM) analysis revealed that all of these carriers showed high magnetic responsiveness after the surface functionalization. Laccase from Cerrena sp. HYB07 was then respectively immobilized covalently on these functionalized magnetic carriers. All the immobilized laccases displayed higher thermostability than free laccase and glutaraldehyde functionalized support (named FSNG) immobilized laccase showed better performance. These immobilized laccases all showed higher efficiency than free laccase for oxidative polymerization of catechol and hydroquinone. The immobilized laccases could be separated from the water insoluble polymerization products. The polymerization product of hydroquinone by FSNG immobilized laccase showed the average polymerization degree of the poly(hydroquinone) was six (DP=6). This work provided a comprehensive exploration of laccase immobilization on magnetic carrier for catalyzing polymerization of phenols.
Keyword ：
Laccase immobilization Laccase immobilization Magnetic nanoparticle Magnetic nanoparticle Phenol polymerization Phenol polymerization
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| GB/T 7714 | Xu, Xinqi , Chen, Tianheng , Xu, Lian et al. Immobilization of laccase on magnetic nanoparticles for enhanced polymerization of phenols [J]. | ENZYME AND MICROBIAL TECHNOLOGY , 2023 , 172 . |
| MLA | Xu, Xinqi et al. "Immobilization of laccase on magnetic nanoparticles for enhanced polymerization of phenols" . | ENZYME AND MICROBIAL TECHNOLOGY 172 (2023) . |
| APA | Xu, Xinqi , Chen, Tianheng , Xu, Lian , Lin, Juan . Immobilization of laccase on magnetic nanoparticles for enhanced polymerization of phenols . | ENZYME AND MICROBIAL TECHNOLOGY , 2023 , 172 . |
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本发明属于生物工程技术领域，具体涉及一种3β‑羟基甾体脱氢酶SfSDR及其在制备去氢表雄酮中的应用。本发明将3β‑羟基甾体脱氢酶SfSDR与葡萄糖脱氢酶BtGDH在大肠埃希氏菌中共表达，并以共表达工程菌的静息细胞作为生物催化剂协同酯酶Z03共同催化3‑乙酰氧基‑△3, 5‑雄甾二烯‑17‑酮合成去氢表雄酮。该生物催化剂具有较高的催化活性、区域选择性和立体选择性，可以在6 h以内完全转化32.8 g/L的3‑乙酰氧基‑△3, 5‑雄甾二烯‑17‑酮生成目标产物去氢表雄酮，无需添加有机溶剂且无副产物产生，经过分离纯化，产物回收率高达95%以上，说明该生物催化剂是去氢表雄酮绿色合成的高效催化剂。
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| GB/T 7714 | 林娟 , 苏冰梅 , 师艺冰 et al. 一种3β-羟基甾体脱氢酶及其在制备去氢表雄酮中的应用 : CN202211028698.9[P]. | 2022-08-25 00:00:00 . |
| MLA | 林娟 et al. "一种3β-羟基甾体脱氢酶及其在制备去氢表雄酮中的应用" : CN202211028698.9. | 2022-08-25 00:00:00 . |
| APA | 林娟 , 苏冰梅 , 师艺冰 , 许炼 , 许鑫琦 . 一种3β-羟基甾体脱氢酶及其在制备去氢表雄酮中的应用 : CN202211028698.9. | 2022-08-25 00:00:00 . |
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