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Yan Z, Huang B, Yang K, Anaman R, Amanze C, Jin J, Zhou H, Qiu G, Zeng W. Enlarging the substrate binding pocket of penicillin G acylase from Achromobacter sp. for highly efficient biosynthesis of β-lactam antibiotics. Bioorg Chem 2023; 136:106533. [PMID: 37084587 DOI: 10.1016/j.bioorg.2023.106533] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/23/2023] [Accepted: 04/05/2023] [Indexed: 04/23/2023]
Abstract
Penicillin G acylase (PGA) is a key biocatalyst for the enzymatic production of β-lactam antibiotics, which can not only catalyze the synthesis of β-lactam antibiotics but also catalyze the hydrolysis of the products to prepare semi-synthetic antibiotic intermediates. However, the high hydrolysis and low synthesis activities of natural PGAs severely hinder their industrial application. In this study, a combinatorial directed evolution strategy was employed to obtain new PGAs with outstanding performances. The best mutant βF24G/βW154G was obtained from the PGA of Achromobacter sp., which exhibited approximately a 129.62-fold and a 52.55-fold increase in specific activity and synthesis/hydrolysis ratio, respectively, compared to the wild-type AsPGA. Thereafter, this mutant was used to synthesize amoxicillin, cefadroxil, and ampicillin; all conversions > 99% were accomplished in 90-135 min with almost no secondary hydrolysis byproducts produced in the reaction. Molecular dynamics simulation and substrate pocket calculation revealed that substitution of the smallest glycine residue at βF24 and βW154 expanded the binding pocket, thereby facilitating the entry and release of substrates and products. Therefore, this novel mutant is a promising catalyst for the large-scale production of β-lactam antibiotics.
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Affiliation(s)
- Zhen Yan
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Bin Huang
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Kai Yang
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Richmond Anaman
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Charles Amanze
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Jing Jin
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Hongbo Zhou
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Guanzhou Qiu
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Weimin Zeng
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China.
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2
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Pan X, Xu L, Li Y, Wu S, Wu Y, Wei W. Strategies to Improve the Biosynthesis of β-Lactam Antibiotics by Penicillin G Acylase: Progress and Prospects. Front Bioeng Biotechnol 2022; 10:936487. [PMID: 35923572 PMCID: PMC9340067 DOI: 10.3389/fbioe.2022.936487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 06/13/2022] [Indexed: 11/13/2022] Open
Abstract
β-Lactam antibiotics are widely used anti-infection drugs that are traditionally synthesized via a chemical process. In recent years, with the growing demand for green alternatives, scientists have turned to enzymatic synthesis. Penicillin G acylase (PGA) is the second most commercially used enzyme worldwide with both hydrolytic and synthetic activities toward antibiotics, which has been used to manufacture the key antibiotic nucleus on an industrial level. However, the large-scale application of PGA-catalyzed antibiotics biosynthesis is still in the experimental stage because of some key limitations, such as low substrate concentration, unsatisfactory yield, and lack of superior biocatalysts. This paper systematically reviews the strategies adopted to improve the biosynthesis of β-lactam antibiotics by adjusting the enzymatic property and manipulating the reaction system in recent 20 years, including mining of enzymes, protein engineering, solvent engineering, in situ product removal, and one-pot reaction cascade. These advances will provide important guidelines for the future use of enzymatic synthesis in the industrial production of β-lactam antibiotics.
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Affiliation(s)
- Xin Pan
- Department of Cardiology, Central Laboratory, The Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
- *Correspondence: Xin Pan, ; Yong Wu, ; Wenping Wei,
| | - Lei Xu
- Department of Cardiology, Central Laboratory, The Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Yaru Li
- Department of Cardiology, Central Laboratory, The Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Sihua Wu
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
- Division of Molecular Science, Graduate School of Science and Technology, Gunma University, Kiryu, Japan
| | - Yong Wu
- Department of Cardiology, Central Laboratory, The Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
- *Correspondence: Xin Pan, ; Yong Wu, ; Wenping Wei,
| | - Wenping Wei
- Department of Cardiology, Central Laboratory, The Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
- *Correspondence: Xin Pan, ; Yong Wu, ; Wenping Wei,
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3
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Li A, Cheng C, Qi W, Pan X, Xu X, Wang X, Wu C, Chu J, He B. Combing multiple site-directed mutagenesis of penicillin G acylase from Achromobacter xylosoxidans PX02 with improved catalytic properties for cefamandole synthesis. Int J Biol Macromol 2021; 175:322-329. [PMID: 33549660 DOI: 10.1016/j.ijbiomac.2021.01.194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 01/28/2021] [Accepted: 01/28/2021] [Indexed: 11/26/2022]
Abstract
Penicillin G acylase (PGA) was an important biocatalyst for enzymatic production of second-generation cephalosporin. PGA from Achromobacter xylosoxidans PX02 (AxPGA) showed relatively lower identity to EcPGA (54.9% in α subunit and 51.7% in β subunit), which could synthesize cefamandole in the kinetically controlled N-acylation (kcNa). Semi-rational design of AxPGA and "small and smart" mutant libraries were developed with minimal screening to improve cefamandole production. A triple mutant αR141A/αF142I/βF24G by combining the mutational sites (βF24, αR141, and αF142) from different subunits of AxPGA showed better performance in cefamandole production, with 4.2-fold of improvement in the (kcat/Km)AD value for activated acyl donor (R)-Methyl mandelate. Meanwhile, the (kcat/Km)Ps value for cefamandole by mutant αR141A/αF142I/βF24G was sharply dropped by 25.5 times, indicating its highly synthetic activity and extremely low hydrolysis of cefamandole. Strikingly, the triple mutant αR141A/αF142I/βF24G could form cefamandole with a yield of 85% at an economical substrate ratio (acyl donor/nucleophile) of 1.3:1 (82% at 1.1:1), which advanced the greener and more sustainable process of cefamandole production than the wild type. Furtherly, the improved synthetic ability and lower hydrolysis of cefamandole by mutant were rationalized using molecular docking.
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Affiliation(s)
- Anni Li
- School of Pharmaceutical Sciences, Nanjing Tech University, Nanjing, Jiangsu 211816, China; College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, Jiangsu 211816, China
| | - Cheng Cheng
- School of Pharmaceutical Sciences, Nanjing Tech University, Nanjing, Jiangsu 211816, China
| | - Weimin Qi
- School of Pharmaceutical Sciences, Nanjing Tech University, Nanjing, Jiangsu 211816, China
| | - Xin Pan
- Department of Cardiology, Department of Central Laboratory, The Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou 225000, China
| | - Xuanping Xu
- School of Pharmaceutical Sciences, Nanjing Tech University, Nanjing, Jiangsu 211816, China
| | - Xinyu Wang
- School of Pharmaceutical Sciences, Nanjing Tech University, Nanjing, Jiangsu 211816, China
| | - Chunying Wu
- School of Pharmaceutical Sciences, Nanjing Tech University, Nanjing, Jiangsu 211816, China
| | - Jianlin Chu
- School of Pharmaceutical Sciences, Nanjing Tech University, Nanjing, Jiangsu 211816, China.
| | - Bingfang He
- School of Pharmaceutical Sciences, Nanjing Tech University, Nanjing, Jiangsu 211816, China.
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4
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Efficient synthesis of β-lactam antibiotics with in situ product removal by a newly isolated penicillin G acylase. Bioorg Chem 2020; 99:103765. [DOI: 10.1016/j.bioorg.2020.103765] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 03/13/2020] [Accepted: 03/14/2020] [Indexed: 12/17/2022]
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Li K, Mohammed MAA, Zhou Y, Tu H, Zhang J, Liu C, Chen Z, Burns R, Hu D, Ruso JM, Tang Z, Liu Z. Recent progress in the development of immobilized penicillin G acylase for chemical and industrial applications: A mini‐review. POLYM ADVAN TECHNOL 2019. [DOI: 10.1002/pat.4791] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Ke Li
- State Key Laboratory of Gansu Advanced Non‐ferrous Metal MaterialsLanzhou University of Technology Lanzhou China
- School of Materials Science and EngineeringLanzhou University of Technology Lanzhou China
| | - Monier Alhadi Abdelrahman Mohammed
- State Key Laboratory of Gansu Advanced Non‐ferrous Metal MaterialsLanzhou University of Technology Lanzhou China
- School of Materials Science and EngineeringLanzhou University of Technology Lanzhou China
| | - Yongshan Zhou
- State Key Laboratory of Gansu Advanced Non‐ferrous Metal MaterialsLanzhou University of Technology Lanzhou China
- School of Materials Science and EngineeringLanzhou University of Technology Lanzhou China
| | - Hongyi Tu
- State Key Laboratory of Gansu Advanced Non‐ferrous Metal MaterialsLanzhou University of Technology Lanzhou China
- School of Materials Science and EngineeringLanzhou University of Technology Lanzhou China
| | - Jiachen Zhang
- State Key Laboratory of Gansu Advanced Non‐ferrous Metal MaterialsLanzhou University of Technology Lanzhou China
- School of Materials Science and EngineeringLanzhou University of Technology Lanzhou China
| | - Chunli Liu
- State Key Laboratory of Gansu Advanced Non‐ferrous Metal MaterialsLanzhou University of Technology Lanzhou China
- School of Materials Science and EngineeringLanzhou University of Technology Lanzhou China
| | - Zhenbin Chen
- State Key Laboratory of Gansu Advanced Non‐ferrous Metal MaterialsLanzhou University of Technology Lanzhou China
- School of Materials Science and EngineeringLanzhou University of Technology Lanzhou China
| | - Robert Burns
- Department of Physics and EngineeringFrostburg State University Frostburg Maryland
| | - Dongdong Hu
- State Key Laboratory of Chemical EngineeringEast China University of Science and Technology Shanghai China
| | - Juan M. Ruso
- Soft Matter and Molecular Biophysics Group, Department of Applied PhysicsUniversity of Santiago de Compostela Santiago de Compostela Spain
| | - Zhenghua Tang
- Guangzhou Key Laboratory for Surface Chemistry of Energy MaterialsNew Energy Research Institute School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre Guangzhou China
- Guangdong Engineering and Technology Research Center for Surface Chemistry of Energy MaterialsSchool of Environment and Energy South China University of Technology, Guangzhou Higher Education Mega Center Guangzhou China
| | - Zhen Liu
- Department of Physics and EngineeringFrostburg State University Frostburg Maryland
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6
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Mayer J, Pippel J, Günther G, Müller C, Lauermann A, Knuuti T, Blankenfeldt W, Jahn D, Biedendieck R. Crystal structures and protein engineering of three different penicillin G acylases from Gram-positive bacteria with different thermostability. Appl Microbiol Biotechnol 2019; 103:7537-7552. [PMID: 31227867 DOI: 10.1007/s00253-019-09977-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 05/16/2019] [Accepted: 06/10/2019] [Indexed: 10/26/2022]
Abstract
Penicillin G acylase (PGA) catalyzes the hydrolysis of penicillin G to 6-aminopenicillanic acid and phenylacetic acid, which provides the precursor for most semisynthetic penicillins. Most applications rely on PGAs from Gram-negative bacteria. Here we describe the first three crystal structures for PGAs from Gram-positive Bacilli and their utilization in protein engineering experiments for the manipulation of their thermostability. PGAs from Bacillus megaterium (BmPGA, Tm = 56.0 °C), Bacillus thermotolerans (BtPGA, Tm = 64.5 °C), and Bacillus sp. FJAT-27231 (FJAT-PGA, Tm = 74.3 °C) were recombinantly produced with B. megaterium, secreted, purified to apparent heterogeneity, and crystallized. Structures with resolutions of 2.20 Å (BmPGA), 2.27 Å (BtPGA), and 1.36 Å (FJAT-PGA) were obtained. They revealed high overall similarity, reflecting the high identity of up to approx. 75%. Notably, the active center displays a deletion of more than ten residues with respect to PGAs from Gram-negatives. This enlarges the substrate binding site and may indicate a different substrate spectrum. Based on the structures, ten single-chain FJAT-PGAs carrying artificial linkers were produced. However, in all cases, complete linker cleavage was observed. While thermostability remained in the wild-type range, the enzymatic activity dropped between 30 and 60%. Furthermore, four hybrid PGAs carrying subunits from two different enzymes were successfully produced. Their thermostabilities mostly lay between the values of the two mother enzymes. For one PGA increased, enzyme activity was observed. Overall, the three novel PGA structures combined with initial protein engineering experiments provide the basis for establishment of new PGA-based biotechnological processes.
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Affiliation(s)
- Janine Mayer
- Institute of Microbiology and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106, Braunschweig, Germany
| | - Jan Pippel
- HZI - Helmholtz Centre for Infection Research, Structure and Function of Proteins, Inhoffenstraße 7, 38124, Braunschweig, Germany
| | - Gabriele Günther
- Institute of Microbiology and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106, Braunschweig, Germany
| | - Carolin Müller
- Institute of Microbiology and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106, Braunschweig, Germany
| | - Anna Lauermann
- Institute of Microbiology and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106, Braunschweig, Germany
| | - Tobias Knuuti
- Institute of Microbiology and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106, Braunschweig, Germany
| | - Wulf Blankenfeldt
- HZI - Helmholtz Centre for Infection Research, Structure and Function of Proteins, Inhoffenstraße 7, 38124, Braunschweig, Germany.,Institute of Biotechnology, Biochemistry and Bioinformatics, Technische Universität Braunschweig, Spielmannstr. 7, 38106, Braunschweig, Germany
| | - Dieter Jahn
- Institute of Microbiology and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106, Braunschweig, Germany
| | - Rebekka Biedendieck
- Institute of Microbiology and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106, Braunschweig, Germany.
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7
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Efficient synthesis of β-lactam antibiotics with very low product hydrolysis by a mutant Providencia rettgeri penicillin G acylase. Appl Microbiol Biotechnol 2018; 102:1749-1758. [PMID: 29306966 DOI: 10.1007/s00253-017-8692-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/30/2017] [Accepted: 12/02/2017] [Indexed: 10/18/2022]
Abstract
Penicillin G acylase (PGA) was isolated from Providencia rettgeri PX04 (PrPGApx04) and utilized for the kinetically controlled synthesis of β-lactam antibiotics. Site-directed mutagenesis was performed to increase the process efficiency. Molecular docking was carried out to speculate the key mutant positions corresponding with synthetic activity, which resulted in the achievement of an efficient mutant, βF24G. It yielded higher conversions than the wild-type enzyme in the synthesis of amoxicillin (95 versus 17.2%) and cefadroxil (95.4 versus 43.2%). The reaction time for achieving the maximum conversion decreased from 14 to 16 h to 2-2.5 h. Furthermore, the secondary hydrolysis of produced antibiotics was hardly observed. Kinetic analysis showed that the (kcat/Km)AD value for the activated acyl donor D-hydroxyphenylglycine methyl ester (D-HPGME) increased up to 41 times. In contrast, the (kcat/Km)Ps values for the products amoxicillin and cefadroxil decreased 6.5 and 21 times, respectively. Consequently, the α value (kcat/Km)Ps/(kcat/Km)AD, which reflected the relative hydrolytic specificity of PGA for produced antibiotics with respect to the activated acyl donor, were only 0.028 and 0.043, respectively. The extremely low hydrolytic activity for the products of the βF24G mutant enabled greater product accumulation to occur during synthesis, which made it a promising enzyme for industrial applications.
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Lakowitz A, Godard T, Biedendieck R, Krull R. Mini review: Recombinant production of tailored bio-pharmaceuticals in different Bacillus strains and future perspectives. Eur J Pharm Biopharm 2017; 126:27-39. [PMID: 28606596 DOI: 10.1016/j.ejpb.2017.06.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 05/30/2017] [Accepted: 06/07/2017] [Indexed: 01/06/2023]
Abstract
Bio-pharmaceuticals like antibodies, hormones and growth factors represent about one-fifth of commercial pharmaceuticals. Host candidates of growing interest for recombinant production of these proteins are strains of the genus Bacillus, long being established for biotechnological production of homologous and heterologous proteins. Bacillus strains benefit from development of efficient expression systems in the last decades and emerge as major industrial workhorses for recombinant proteins due to easy cultivation, non-pathogenicity and their ability to secrete recombinant proteins directly into extracellular medium allowing cost-effective downstream processing. Their broad product portfolio of pharmaceutically relevant recombinant proteins described in research include antibody fragments, growth factors, interferons and interleukins, insulin, penicillin G acylase, streptavidin and different kinases produced in various cultivation systems like microtiter plates, shake flasks and bioreactor systems in batch, fed-batch and continuous mode. To further improve production and secretion performance of Bacillus, bottlenecks and limiting factors concerning proteases, chaperones, secretion machinery or feedback mechanisms can be identified on different cell levels from genomics and transcriptomics via proteomics to metabolomics and fluxomics. For systematical identification of recurring patterns characteristic of given regulatory systems and key genetic targets, systems biology and omics-technology provide suitable and promising approaches, pushing Bacillus further towards industrial application for recombinant pharmaceutical protein production.
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Affiliation(s)
- Antonia Lakowitz
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Rebenring 56, 38106 Braunschweig, Germany; Center of Pharmaceutical Engineering (PVZ), Technische Universität Braunschweig, Franz-List-Straβe 35a, 38106 Braunschweig, Germany; Braunschweig Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106 Braunschweig, Germany
| | - Thibault Godard
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Rebenring 56, 38106 Braunschweig, Germany; Center of Pharmaceutical Engineering (PVZ), Technische Universität Braunschweig, Franz-List-Straβe 35a, 38106 Braunschweig, Germany; Braunschweig Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106 Braunschweig, Germany
| | - Rebekka Biedendieck
- Braunschweig Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106 Braunschweig, Germany; Institute of Microbiology, Technische Universität Braunschweig, Rebenring 56, 38106 Braunschweig, Germany
| | - Rainer Krull
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Rebenring 56, 38106 Braunschweig, Germany; Center of Pharmaceutical Engineering (PVZ), Technische Universität Braunschweig, Franz-List-Straβe 35a, 38106 Braunschweig, Germany; Braunschweig Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Rebenring 56, 38106 Braunschweig, Germany.
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9
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Deng S, Su E, Ma X, Yang S, Wei D. Efficient enzymatic synthesis of ampicillin by mutant Alcaligenes faecalis penicillin G acylase. J Biotechnol 2015; 199:62-8. [DOI: 10.1016/j.jbiotec.2015.01.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 12/24/2014] [Accepted: 01/07/2015] [Indexed: 10/24/2022]
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10
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Current state and perspectives of penicillin G acylase-based biocatalyses. Appl Microbiol Biotechnol 2014; 98:2867-79. [DOI: 10.1007/s00253-013-5492-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 12/20/2013] [Accepted: 12/22/2013] [Indexed: 10/25/2022]
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Rapid Identification of Polyhydroxyalkanoate Accumulating Members of Bacillales Using Internal Primers for phaC Gene of Bacillus megaterium. ACTA ACUST UNITED AC 2013. [DOI: 10.1155/2013/562014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Bacillus megaterium is gaining recognition as an experimental model and biotechnologically important microorganism. Recently, descriptions of new strains of B. megaterium and closely related species isolated from diverse habitats have increased. Therefore, its identification requires several tests in combination which is usually time consuming and difficult to do. We propose using the uniqueness of the polyhydroxyalkanoate synthase C gene of B. megaterium in designing primers that amplify the 0.9 kb region of the phaC for its identification. The PCR method was optimized to amplify 0.9 kb region of phaC gene. After optimization of the PCR reaction, two methods were investigated in detail. Method I gave an amplification of a single band of 0.9 kb only in B. megaterium and was demonstrated by several strains of B. megaterium isolated from different habitats. The use of Method I did not result in the amplification of the phaC gene with other members of Bacillales. The specificity for identification of B. megaterium was confirmed using sequencing of amplicon and RT-PCR. Method II showed multiple banding patterns of nonspecific amplicons among polyhydroxyalkanoate accumulating members of Bacillales unique to the respective species. These methods are rapid and specific for the identification of polyhydroxyalkanoate accumulating B. megaterium and members of Bacillales.
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12
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Jager SA, Shapovalova IV, Jekel PA, Alkema WB, Švedas VK, Janssen DB. Saturation mutagenesis reveals the importance of residues αR145 and αF146 of penicillin acylase in the synthesis of β-lactam antibiotics. J Biotechnol 2008; 133:18-26. [DOI: 10.1016/j.jbiotec.2007.08.039] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2007] [Revised: 08/21/2007] [Accepted: 08/24/2007] [Indexed: 11/25/2022]
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