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Chen B, Wu X, Xiong J, Zong MH, Cheng JH, Ge J, Lou WY. Biomimetic Mineralization of Prussian Blue Analogue-Incorporated Glucose Oxidase Hybrid Catalyst for Glucose Detection. Catal Letters 2021. [DOI: 10.1007/s10562-021-03668-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Jia HY, Yang ZY, Chen Q, Zong MH, Li N. Engineering Promiscuous Alcohol Dehydrogenase Activity of a Reductive Aminase AspRedAm for Selective Reduction of Biobased Furans. Front Chem 2021; 9:610091. [PMID: 34055734 PMCID: PMC8155666 DOI: 10.3389/fchem.2021.610091] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 02/15/2021] [Indexed: 11/25/2022] Open
Abstract
Catalytic promiscuity is a promising starting point for improving the existing enzymes and even creating novel enzymes. In this work, site-directed mutagenesis was performed to improve promiscuous alcohol dehydrogenase activity of reductive aminase from Aspergillus oryzae (AspRedAm). AspRedAm showed the cofactor preference toward NADPH in reductive aminations, while it favored NADH in the reduction reactions. Some key amino acid residues such as N93, I118, M119, and D169 were identified for mutagenesis by molecular docking. Variant N93A showed the optimal pH and temperature of 8 and 30°C, respectively, in the reduction of 5-hydroxymethylfurfural (HMF). The thermostability was enhanced upon mutation of N93 to alanine. The catalytic efficiency of variant N93A (kcat/Km, 23.6 mM−1 s−1) was approximately 2-fold higher compared to that of the wild-type (WT) enzyme (13.1 mM−1 s−1). The improved catalytic efficiency of this variant may be attributed to the reduced steric hindrance that stems from the smaller side chain of alanine in the substrate-binding pocket. Both the WT enzyme and variant N93A had broad substrate specificity. Escherichia coli (E. coli) cells harboring plain vector enabled selective reduction of biobased furans to target alcohols, with the conversions of 35–95% and the selectivities of >93%. The introduction of variant N93A to E. coli resulted in improved substrate conversions (>98%) and selectivities (>99%).
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Zhang ZH, Li MF, Peng F, Zhong SR, Huang Z, Zong MH, Lou WY. Oxidized high-amylose starch macrogel as a novel delivery vehicle for probiotic and bioactive substances. Food Hydrocoll 2021. [DOI: 10.1016/j.foodhyd.2020.106578] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Wu X, Xiong J, Liu S, Zong MH, Lou WY. A Versatile Competitive Coordination Strategy for Tailoring Bioactive Zeolitic Imidazolate Framework Composites. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2007586. [PMID: 33825336 DOI: 10.1002/smll.202007586] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 03/17/2021] [Indexed: 06/12/2023]
Abstract
Zeolitic imidazolate frameworks (ZIFs) serving as platforms for bioactive guest encapsulation have attracted growing attention, yet the tailoring of its architectures and bioactivity remains a major challenge. Herein, a versatile competitive coordination strategy is proposed by using amorphous zinc nucleotide gel as template for step-by-step growth of ZIFs, which enables the tailoring of bioactive ZIF composites under facile conditions. Mechanism investigation reveals that introduced nucleotide determines the hierarchical pore structure and hydrophilicity, leading to customized activity retention and stability of the resultant bioactive ZIF composites. Furthermore, nucleoside monophosphate enhances the acidic tolerance of ZIFs. To the authors' knowledge, this is the first example showing the dynamic evolution of amorphous gels to crystalline ZIFs for in situ encapsulation of enzymes with tailored catalytic performance. This study provides insights for rational design of ZIF-based biocomposites and broadens the application of bioactive metal-organic frameworks.
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Feng K, Zhai MY, Wei YS, Zong MH, Wu H, Han SY. Fabrication of Nano/Micro-Structured Electrospun Detection Card for the Detection of Pesticide Residues. Foods 2021; 10:889. [PMID: 33921560 PMCID: PMC8073816 DOI: 10.3390/foods10040889] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/11/2021] [Accepted: 04/13/2021] [Indexed: 12/11/2022] Open
Abstract
A novel nano/micro-structured pesticide detection card was developed by combining electrospinning and hydrophilic modification, and its feasibility for detecting different pesticides was investigated. Here, the plain and hydrophilic-modified poly(ε-caprolactone) (PCL) fiber mats were used for the absorption of indolyl acetate and acetylcholinesterase (AChE), respectively. By pre-treating the fiber mat with ethanol, its surface wettability was improved, thus, promoting the hydrolysis of the PCL fiber mat. Furthermore, the absorption efficiency of AChE was improved by almost two times due to the increased hydrophilicity of the modified fiber mat. Noteworthily, this self-made detection card showed a 5-fold, 2-fold, and 1.5-fold reduction of the minimum detectable concentration for carbofuran, malathion, and trichlorfon, respectively, compared to the national standard values. Additionally, it also exhibited good stability when stored at 4 °C and room temperature. The food detection test showed that this nano/micro-based detection card had better detectability than the commercial detection card. Therefore, this study offers new insights into the design of pesticide detection cards, which also broadens the application of electrospinning technique.
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Liao HX, Jia HY, Dai JR, Zong MH, Li N. Bioinspired Cooperative Photobiocatalytic Regeneration of Oxidized Nicotinamide Cofactors for Catalytic Oxidations. CHEMSUSCHEM 2021; 14:1615. [PMID: 33764662 DOI: 10.1002/cssc.202100471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Invited for this month's cover is the group of Ning Li at South China University of Technology. The image shows an efficient photobiocatalytic system to regenerate oxidized nicotinamide cofactors for dehydrogenase-mediated oxidations. The Communication itself is available at 10.1002/cssc.202100184.
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Liao HX, Jia HY, Dai JR, Zong MH, Li N. Bioinspired Cooperative Photobiocatalytic Regeneration of Oxidized Nicotinamide Cofactors for Catalytic Oxidations. CHEMSUSCHEM 2021; 14:1687-1691. [PMID: 33559949 DOI: 10.1002/cssc.202100184] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 02/05/2021] [Indexed: 06/12/2023]
Abstract
Inspired by water-forming NAD(P)H oxidases, a cooperative photobiocatalytic system has been designed to aerobically regenerate the oxidized nicotinamide cofactors. Photocatalysts enable NAD(P)H oxidation with O2 under visible-light irradiation, producing H2 O2 as a byproduct, which is subsequently used as an oxidant by the horseradish peroxidase mediator system (PMS) to oxidize NAD(P)H. The photobiocatalytic system shows a turnover frequency of 8800 min-1 in the oxidation of NAD(P)H. Photobiocatalytic NAD(P)H oxidation proceeds smoothly at pH 6-9. In addition to natural NAD(P)H, synthetic biomimetics are also good substrates for this regeneration system. Total turnover numbers of up to 180000 are obtained for the cofactor when the photobiocatalytic regeneration system is coupled with dehydrogenase-catalyzed oxidations. It may be a promising protocol to recycle the oxidized cofactors for catalytic oxidations.
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Feng K, Li SF, Wei YS, Zong MH, Hu TG, Wu H, Han SY. Fabrication of nanostructured multi-unit vehicle for intestinal-specific delivery and controlled release of peptide. NANOTECHNOLOGY 2021; 32:245101. [PMID: 33690179 DOI: 10.1088/1361-6528/abed07] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 03/09/2021] [Indexed: 06/12/2023]
Abstract
An oral multi-unit delivery system was developed by incorporating the nanoparticle (NP) into the nanofiber mat and its efficiency for intestinal-specific delivery and controlled release of a peptide (insulin) was investigated. Initially, the influence of deacetylation degree (DD) of chitosan and ionic gelation methods on the properties of NPs was studied. High DD (95%) chitosan was attributed to higher encapsulation efficiency and stability when crosslinked with polyanion tripolyphosphate. Subsequently, the multi-unit system was fabricated using a pH-sensitive polymer (sodium alginate) as the coating layer to further encapsulate the NP. Fiber mat with an average diameter of 481 ± 47 nm could significantly decrease the burst release of insulin in acidic condition and release most amount of insulin (>60%) in the simulated intestinal medium. Furthermore, the encapsulated peptide remained in good integrity. This multi-unit carrier provides the better-designed vehicle for intestinal-specific delivery and controlled release of the peptide.
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Wei YS, Feng K, Li SF, Hu TG, Linhardt RJ, Zong MH, Wu H. Oral fate and stabilization technologies of lactoferrin: a systematic review. Crit Rev Food Sci Nutr 2021; 62:6341-6358. [PMID: 33749401 DOI: 10.1080/10408398.2021.1900774] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Lactoferrin (Lf), a bioactive protein initially found in many biological secretions including milk, is regarded as the nutritional supplement or therapeutic ligand due to its multiple functions. Research on its mode of action reveals that intact Lf or its active peptide (i.e., lactoferricin) shows an important multifunctional performance. Oral delivery is considered as the most convenient administration route for this bioactive protein. Unfortunately, Lf is sensitive to the gastrointestinal (GI) physicochemical stresses and lactoferricin is undetectable in GI digesta. This review introduces the functionality of Lf at the molecular level and its degradation behavior in GI tract is discussed in detail. Subsequently, the absorption and transport of Lf from intestine into the blood circulation, which is pivotal to its health promoting effects in various tissues, and some assisting labeling methods are discussed. Stabilization technologies aiming at preserving the structural integrity and functional properties of orally administrated Lf are summarized and compared. Altogether, this work comprehensively reviews the structure-function relationship of Lf, its oral fate and the development of stabilization technologies for the enhancement of the oral bioavailability of Lf. The existing limitations and scope for future research are also discussed.
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Xu P, Zhang SY, Luo ZG, Zong MH, Li XX, Lou WY. Biotechnology and bioengineering of pullulanase: state of the art and perspectives. World J Microbiol Biotechnol 2021; 37:43. [PMID: 33547538 DOI: 10.1007/s11274-021-03010-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 01/19/2021] [Indexed: 11/26/2022]
Abstract
Pullulanase (EC 3.2.1.41) is a starch-debranching enzyme in the α-amylase family and specifically cleaves α-1,6-glycosidic linkages in starch-type polysaccharides, such as pullulan, β-limited dextrin, glycogen, and amylopectin. It plays a key role in debranching and hydrolyzing starch completely, thus bring improved product quality, increased productivity, and reduced production cost in producing resistant starch, sugar syrup, and beer. Plenty of researches have been made with respects to the discovery of either thermophilic or mesophilic pullulanases, however, few examples meet the demand of industrial application. This review presents the progress made in the recent years from the first aspect of characteristics of pullulanases. The heterologous expression of pullulanases in different microbial hosts and the methods used to improve the expression effectiveness and the regulation of enzyme production are also described. Then, the function evolution of pullulanases from a protein engineering view is discussed. In addition, the immobilization strategy using novel materials is introduced to improve the recyclability of pullulanases. At the same time, we indicate the trends in the future research to facilitate the industrial application of pullulanases.
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Su HH, Peng F, Ou XY, Zeng YJ, Zong MH, Lou WY. Combinatorial synthetic pathway fine-tuning and cofactor regeneration for metabolic engineering of Escherichia coli significantly improve production of D-glucaric acid. N Biotechnol 2020; 59:51-58. [PMID: 32693027 DOI: 10.1016/j.nbt.2020.03.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 03/18/2020] [Accepted: 03/28/2020] [Indexed: 12/21/2022]
Abstract
D-glucaric acid (GA) has been identified as among promising biotechnological alternatives to oil-based chemicals. GA and its derivatives are widely used in food additives, dietary supplements, drugs, detergents, corrosion inhibitors and biodegradable materials. The increasing availability of a GA market is improving the cost-effectiveness and efficiency of various biosynthetic pathways. In this study, an engineered Escherichia coli strain GA10 was constructed by systematic metabolic engineering. This involved redirecting metabolic flux into the GA biosynthetic pathways, blocking the conversion pathways of d-glucuronic acid (GlcA) and GA into by-products, introducing an in situ NAD+ regeneration system and fine-tuning the activity of the key enzyme, myo-inositol oxygenase (Miox). Subsequently, the culture medium was optimized to achieve the best performance of the GA10 strain. GA was produced at 5.35 g/L (extracellular and intracellular), with a maximized yield of ∼0.46 mol/mol on d-glucose and glycerol, by batch fermentation. This work demonstrates efficient biosynthetic pathways of GA in E. coli by metabolic engineering and should accelerate the application of GA biosynthetic pathways in industrial processes.
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Li FZ, Zeng YJ, Zong MH, Yang JG, Lou WY. Bioprospecting of a novel endophytic Bacillus velezensis FZ06 from leaves of Camellia assamica: Production of three groups of lipopeptides and the inhibition against food spoilage microorganisms. J Biotechnol 2020; 323:42-53. [PMID: 32739396 DOI: 10.1016/j.jbiotec.2020.07.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 07/24/2020] [Accepted: 07/28/2020] [Indexed: 02/06/2023]
Abstract
Food contamination caused by microorganisms has become a threat to consumers' health. Exploring antagonistic endophytes from plants of food raw-material and applying bioactive metabolites to inhibit the contamination has been an alternative and safer solution. In this study, we isolated and screened potential antagonistic endophytes from fresh Camellia assamica leaves, which were widely used in tea beverage production. We focused on a strain that showed visible inhibitory activity to Gram-positive bacteria, Gram-negative bacteria, and fungi. It was identified as a member of Bacillus velezensis and named FZ06. The results of genome analysis showed the strain FZ06 had 167 single-copy specific genes, much higher than those of most related strains. Also, 11 potential gene clusters of antimicrobial metabolites were found. Three groups of lipopeptides (surfactin, iturin, and fengycin) were identified by UPLC-MS/MS in purified antimicrobial methanol fraction of strain FZ06. The results of minimum inhibitory concentration (MIC) test proved the lipopeptide extract showed significant inhibitory effect on food spoilage bacteria (MIC 512-2048 μg/mL) and toxigenic fungi (MIC 128-256 μg/mL). In conclusion, this study suggests that the endophytic B. velezensis FZ06 and its lipopeptide extract hold great potential applications in the inhibition of food spoilage bacteria and toxic fungi in food industry.
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Guo ZW, Ou XY, Liang S, Gao HF, Zhang LY, Zong MH, Lou WY. Recruiting a Phosphite Dehydrogenase/Formamidase-Driven Antimicrobial Contamination System in Bacillus subtilis for Nonsterilized Fermentation of Acetoin. ACS Synth Biol 2020; 9:2537-2545. [PMID: 32786356 DOI: 10.1021/acssynbio.0c00312] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Microbial contamination, especially in large-scale processes, is partly a life-or-death issue for industrial fermentation. Therefore, the aim of this research was to create an antimicrobial contamination system in Bacillus subtilis 168 (an ideal acetoin producer for its safety and acetoin synthesis potential). First, introduction of the formamidase (FmdA) from Helicobacter pylori and the phosphite dehydrogenase (PtxD) from Pseudomonas stutzeri enabled the engineered Bacillus subtilis to simultaneously assimilate formamide and phosphite as nitrogen (N) and phosphorus (P) sources. Thus, the engineered B. subtilis became the dominant population in a potentially contaminated system, while contaminated microbes were starved of key nutrients. Second, stepwise metabolic engineering via chromosome-based overexpression of the relevant glycolysis and acetoin biosynthesis genes led to a 1.12-fold increment in acetoin titer compared with the starting host. Finally, with our best acetoin producer, 25.56 g/L acetoin was synthesized in the fed-batch fermentation, with a productivity of 0.33 g/L/h and a yield of 0.37 g/g under a nonsterilized and antibiotic-free system. More importantly, our work fulfills many key criteria of sustainable chemistry since sterilization is abolished, contributing to the simplified fermentation operation with lower energy consumption and cost.
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Zhang LS, Chu MY, Zong MH, Yang JG, Lou WY. Facile and Green Production of Human Milk Fat Substitute through Rhodococcus opacus Fermentation. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:9368-9376. [PMID: 32700528 DOI: 10.1021/acs.jafc.0c03185] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Human milk fat substitute (HMFS) is a class of structured lipids widely used in infant formulas. Herein, HMFS was prepared by Rhodococcus opacus fermentation. The substrate oils suitable for HMFS production were coconut oil (66.1-57.5%), soybean oil (17.5-26.5%), high oleic acid sunflower oil (5.4-4.5%), Antarctic krill oil (9-9.5%), and fungal oil (2%). Six HMFSs were prepared, among which HMFS V and VI were similar to human milk fat from Chinese in terms of fatty acid composition and triacylglycerol species. The sn-2 position of HMFS was occupied by palmitic acid (49.31 and 43.48% in HMFS V and VI, respectively). The major triacylglycerols were OPL, OPO, and LPL, accounting for 15.90, 9.49, and 6.84 and 17.52, 8.44, and 8.55% in HMFS V and VI, respectively. This study is the first to prepare structured lipids intended for infant formula through fermentation, providing a novel strategy for the edible oil industry.
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Zhai MY, Feng K, Hu TG, Zong MH, Wu H. Development of a novel nano-based detection card by electrospinning for rapid and sensitive analysis of pesticide residues. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2020; 100:4400-4408. [PMID: 32388876 DOI: 10.1002/jsfa.10477] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Revised: 04/08/2020] [Accepted: 05/01/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Increasing food safety awareness of consumers promotes the development of rapid and sensitive detection techniques for pesticide residues. In this study, a new type of rapid detection card for organophosphorus and carbamate pesticide residues was developed by electrospinning. The card involved enzyme fiber mat (EFM) and substrate fiber mat (SFM) which were prepared by mixing poly(vinyl alcohol) with acetylcholinesterase (AChE) and indolyl acetate (IA), respectively. RESULTS The mean diameter of fibers was 240 ± 53 nm for EFM and 387 ± 84 nm for SFM. Results of Fourier transform infrared and X-ray photoelectron spectroscopies confirmed that AChE and IA were successfully encapsulated into the fibers. The minimum concentrations of AChE and IA for effective detection were 1 and 3 mg mL-1 , respectively, and the optimal detection time was 15 min. The limits of detection for this card were 0.5 mg L-1 for omethoate, 1.5 mg L-1 for malathion, 0.1 mg L-1 for carbaryl and 0.02 mg L-1 for carbofuran. The detection card exhibited good storage stability and its activity could be maintained when stored at room temperature for at least 4 months. Additionally, the EFM can be reused three times. CONCLUSIONS The detection card obtained here was superior to a commercial card in detecting pesticide residues in real food samples. Hence, this electrospun detection card has potential for simple, rapid and sensitive analysis of pesticide residues. © 2020 Society of Chemical Industry.
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Teng MJ, Wei YS, Hu TG, Zhang Y, Feng K, Zong MH, Wu H. Citric acid cross-linked zein microcapsule as an efficient intestine-specific oral delivery system for lipophilic bioactive compound. J FOOD ENG 2020. [DOI: 10.1016/j.jfoodeng.2020.109993] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Zhang LS, Chu MY, Zong MH, Yang JG, Lou WY. Carbon source modify lipids composition of Rhodococcus opacus intended for infant formula. J Biotechnol 2020; 319:8-14. [PMID: 32470464 DOI: 10.1016/j.jbiotec.2020.05.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 05/04/2020] [Accepted: 05/20/2020] [Indexed: 01/24/2023]
Abstract
Human milk fat substitutes (HMFSs) are the structured lipids intended for infant formula. It provides energy and essential fatty acid for infant. HMFSs are mainly prepared by enzymatic method. In this study, we aim to explore the potential for producing HMFSs by fermentation using R. opacus. The results indicated that different compounds with chain length from 12 to 18, used as carbon source, could be incorporated into triacylglycerols directly. Polyunsaturated fatty acids in term of ARA, EPA, DHA could enter the kennedy pathway directly and involved in the biosynthesis of triacylglycerols. GC, UPLC-MS and 13C-NMR analysis demonstrated that typical structured lipids β-OPL (40.09%) was synthesized in R. opacus. Transcriptome analysis revealed that β-oxidation, fatty acid elongation and kennedy pathways existed in R. opacus. It was concluded that fatty acid supplied as carbon source could enter the kennedy pathways directly or via the de novo fatty acid biosynthesis pathway depending on the chain length, thus, affect the triacylglycerol species formed in the Rhodococcus opacus.
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Xiong J, Cao SL, Zong MH, Lou WY, Wu XL. Biosynthesis of Alanyl-Histidine Dipeptide Catalyzed by Papain Immobilized on Magnetic Nanocrystalline Cellulose in Deep Eutectic Solvents. Appl Biochem Biotechnol 2020; 192:573-584. [DOI: 10.1007/s12010-020-03345-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 05/22/2020] [Indexed: 11/28/2022]
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Wei P, Chao P, Wang YY, Li DL, Zou QJ, Zong MH, Lou WY. Marked improvement in the asymmetric reduction of 2-hydroxyacetophenone with mut-AcCR in a biphasic system. MOLECULAR CATALYSIS 2020. [DOI: 10.1016/j.mcat.2020.110903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Yang ZY, Wen M, Zong MH, Li N. Synergistic chemo/biocatalytic synthesis of 2,5-furandicarboxylic acid from 5-hydroxymethylfurfural. CATAL COMMUN 2020. [DOI: 10.1016/j.catcom.2020.105979] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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Wei YS, Niu ZC, Wang FQ, Feng K, Zong MH, Wu H. A novel Pickering emulsion system as the carrier of tocopheryl acetate for its application in cosmetics. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 109:110503. [PMID: 32228963 DOI: 10.1016/j.msec.2019.110503] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/01/2019] [Accepted: 11/26/2019] [Indexed: 12/24/2022]
Abstract
Pickering emulsion (PE) stabilized by bio-compatible polymer nanoparticles (NPs) was first developed for the encapsulation of lipophilic tocopheryl acetate (TA) for its application in cosmetics. The poly(lactide-co-glycolide) (PLGA)/poly(styrene-co-4-styrene-sulfonate) (PSS) NPs were prepared by solvent displacement, and then they were used as emulsifier particles to fabricate TA-encapsulated PE. It was found that the TA encapsulation efficiency was >98%. Scanning electron microscope analysis showed that the obtained PE exhibited 'shell' structure. The PE droplets had spherical shape with diameter around 2 μm and good dispersibility as evidenced by laser scanning confocal microscope. In addition, the PE was stable at the pH range of 4.29-7.07 which was compatible to skin pH. Meanwhile, the PE also showed good storage stability since there was no obvious change in its diameter, PDI and TA retention after storage at 4 °C for 30 days. The DPPH method confirmed that TA retained its antioxidation in the PE preparation process. Moreover, an improved UV irradiation stability was observed for the TA after being encapsulated in the PE. The results of cytotoxicity test suggested that the PE was compatible to the Hacat cell line (human immortalized keratinocytes). And there is negligible influence in the cellular uptake of TA after its encapsulation in the PE. However, the cellular antioxidant activity (CAA) of encapsulated TA presented a significant increase from 1.32 to 1.56 μM quercetin equivalent/mg·mL-1. Hence, the prepared PE was promising as the carrier of TA for its cosmetic application.
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Zhang SY, Guo ZW, Wu XL, Ou XY, Zong MH, Lou WY. Recombinant expression and characterization of a novel cold-adapted type I pullulanase for efficient amylopectin hydrolysis. J Biotechnol 2020; 313:39-47. [DOI: 10.1016/j.jbiotec.2020.03.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 03/14/2020] [Accepted: 03/16/2020] [Indexed: 01/01/2023]
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Peng F, Su HH, Ou XY, Ni ZF, Zong MH, Lou WY. Immobilization of Cofactor Self-Sufficient Recombinant Escherichia coli for Enantioselective Biosynthesis of ( R)-1-Phenyl-1,2-Ethanediol. Front Bioeng Biotechnol 2020; 8:17. [PMID: 32154222 PMCID: PMC7046757 DOI: 10.3389/fbioe.2020.00017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 01/09/2020] [Indexed: 11/18/2022] Open
Abstract
(R)-1-phenyl-1,2-ethanediol is an important synthon for the preparation of β-adrenergic blocking agents. This study identified a (2R,3R)-butanediol dehydrogenase (KgBDH) from Kurthia gibsonii SC0312, which showed high enantioselectivity for production of (R)-1-phenyl-1,2-ethanediol by reduction of 2-hydroxyacetophenone. KgBDH was expressed in a recombinant engineered strain, purified, and characterized. It showed good catalytic activity at pH 6–8 and better stability in alkaline (pH 7.5–8) than an acidic environment (pH 6.0–7.0), providing approximately 73 and 88% of residual activity after 96 h at pH 7.5 and 8.0, respectively. The maximum catalytic activity was obtained at 45°C; nevertheless, poor thermal stability was observed at >30°C. Additionally, the examined metal ions did not activate the catalytic activity of KgBDH. A recombinant Escherichia coli strain coexpressing KgBDH and glucose dehydrogenase (GHD) was constructed and immobilized via entrapment with a mixture of activated carbon and calcium alginate via entrapment. The immobilized cells had 1.8-fold higher catalytic activity than that of cells immobilized by calcium alginate alone. The maximum catalytic activity of the immobilized cells was achieved at pH 7.5, and favorable pH stability was observed at pH 6.0–9.0. Moreover, the immobilized cells showed favorable thermal stability at 25–30°C and better operational stability than free cells, retaining approximately 55% of the initial catalytic activity after four cycles. Finally, 81% yields (195 mM product) and >99% enantiomeric excess (ee) of (R)-1-phenyl-1,2-ethanediol were produced within 12 h through a fed-batch strategy with the immobilized cells (25 mg/ml wet cells) at 35°C and 180 rpm, with a productivity of approximately 54 g/L per day.
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Liang S, Wu XL, Xiong J, Zong MH, Lou WY. Metal-organic frameworks as novel matrices for efficient enzyme immobilization: An update review. Coord Chem Rev 2020. [DOI: 10.1016/j.ccr.2019.213149] [Citation(s) in RCA: 124] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Peng F, Chen QS, Li FZ, Ou XY, Zong MH, Lou WY. Using deep eutectic solvents to improve the biocatalytic reduction of 2-hydroxyacetophenone to (R)-1-phenyl-1,2-ethanediol by Kurthia gibsonii SC0312. MOLECULAR CATALYSIS 2020. [DOI: 10.1016/j.mcat.2020.110773] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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