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Malmir N, Zamani M, Motallebi M, Fard NA, Mekuto L. Cyanide Biodegradation by Trichoderma harzianum and Cyanide Hydratase Network Analysis. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27103336. [PMID: 35630813 PMCID: PMC9143735 DOI: 10.3390/molecules27103336] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 05/13/2022] [Accepted: 05/14/2022] [Indexed: 11/23/2022]
Abstract
Cyanide is a poisonous and dangerous chemical that binds to metals in metalloenzymes, especially cytochrome C oxidase and, thus, interferes with their functionalities. Different pathways and enzymes are involved during cyanide biodegradation, and cyanide hydratase is one of the enzymes that is involved in such a process. In this study, cyanide resistance and cyanide degradation were studied using 24 fungal strains in order to find the strain with the best capacity for cyanide bioremediation. To confirm the capacity of the tested strains, cyano-bioremediation and the presence of the gene that is responsible for the cyanide detoxification was assessed. From the tested organisms, Trichoderma harzianum (T. harzianum) had a significant capability to resist and degrade cyanide at a 15 mM concentration, where it achieved an efficiency of 75% in 7 days. The gene network analysis of enzymes that are involved in cyanide degradation revealed the involvement of cyanide hydratase, dipeptidase, carbon–nitrogen hydrolase-like protein, and ATP adenylyltransferase. This study revealed that T. harzianum was more efficient in degrading cyanide than the other tested fungal organisms, and molecular analysis confirmed the experimental observations.
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Affiliation(s)
- Narges Malmir
- National Institute of Genetic Engineering and Biotechnology (NIGEB), Shahrak-e Pajoohesh km 15, Tehran-Karaj Highway, Tehran P.O. Box 14965/161, Iran; (N.M.); (M.Z.); (M.M.); (N.A.F.)
- Department of Chemical Engineering, University of Johannesburg, Johannesburg 2028, South Africa
| | - Mohammadreza Zamani
- National Institute of Genetic Engineering and Biotechnology (NIGEB), Shahrak-e Pajoohesh km 15, Tehran-Karaj Highway, Tehran P.O. Box 14965/161, Iran; (N.M.); (M.Z.); (M.M.); (N.A.F.)
- Department of Chemical Engineering, University of Johannesburg, Johannesburg 2028, South Africa
| | - Mostafa Motallebi
- National Institute of Genetic Engineering and Biotechnology (NIGEB), Shahrak-e Pajoohesh km 15, Tehran-Karaj Highway, Tehran P.O. Box 14965/161, Iran; (N.M.); (M.Z.); (M.M.); (N.A.F.)
- Department of Chemical Engineering, University of Johannesburg, Johannesburg 2028, South Africa
| | - Najaf Allahyari Fard
- National Institute of Genetic Engineering and Biotechnology (NIGEB), Shahrak-e Pajoohesh km 15, Tehran-Karaj Highway, Tehran P.O. Box 14965/161, Iran; (N.M.); (M.Z.); (M.M.); (N.A.F.)
- Department of Chemical Engineering, University of Johannesburg, Johannesburg 2028, South Africa
| | - Lukhanyo Mekuto
- Department of Chemical Engineering, University of Johannesburg, Johannesburg 2028, South Africa
- Correspondence: ; Tel.: +27-(0)-11-559-9212
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Potential of the Signal Peptide Derived from the PAS_chr3_0030 Gene Product for Secretory Expression of Valuable Enzymes in Pichia pastoris. Appl Environ Microbiol 2022; 88:e0029622. [PMID: 35435711 DOI: 10.1128/aem.00296-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pichia pastoris is widely used for the production of valuable recombinant proteins. An advantage of P. pastoris over other expression systems is that it secretes low levels of endogenous proteins, which facilitates the purification processes if the desired recombinant proteins are efficiently secreted into the culture medium. However, not all recombinant proteins can be successfully secreted by P. pastoris, especially enzymes that are located in intracellular compartments in their native hosts. Few studies have reported strategies for releasing recombinant proteins which cannot be secreted by standard protocols. Here, we investigated whether this challenge can be addressed using novel secretion leaders. Analysis of the secretome and transcriptome of P. pastoris indicated that the four genes with the highest protein-to-transcript ratios were EPX1, PAS_chr3_0030, SCW10, and UTH1, suggesting that their gene products contain efficient secretion leaders. Our data revealed that the signal peptide derived from the PAS_chr3_0030 gene product conferred secretion competence to certain industrial enzymes, e.g., a nitrilase of Alcaligenes faecalis ZJUTB10, a ribosylnicotinamide kinase of P. pastoris, and a glucose dehydrogenase of Exiguobacterium sibiricum. Therefore, the signal peptide derived from the PAS_chr3_0030 gene product represents a novel secretion sequence for the secretory expression of recombinant enzymes in P. pastoris. IMPORTANCE Although P. pastoris is widely used for the secretory production of pharmaceutical proteins, its successful applications in the secretory production of industrial enzymes are limited. The α-mating factor pre-pro leader is the most widely used secretion signal in P. pastoris, but numerous industrial enzymes cannot be secreted using it. The importance of this study is that we identified a signal peptide derived from the PAS_chr3_0030 gene product which conferred secretion competence to three-quarters of the enzymes tested. This signal peptide derived from the PAS_chr3_0030 gene product may facilitate the application of P. pastoris in industrial biocatalysis.
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Shen JD, Cai X, Liu ZQ, Zheng YG. Nitrilase: a promising biocatalyst in industrial applications for green chemistry. Crit Rev Biotechnol 2020; 41:72-93. [PMID: 33045860 DOI: 10.1080/07388551.2020.1827367] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Nitrilases are widely distributed in nature and are able to hydrolyze nitriles into their corresponding carboxylic acids and ammonia. In industry, nitrilases have been used as green biocatalysts for the production of high value-added products. To date, biocatalysts are considered to be important alternatives to chemical catalysts due to increasing environmental problems and resource scarcity. This review provides an overview of recent advances of nitrilases in aspects of distribution, enzyme screening, molecular structure and catalytic mechanism, protein engineering, and their potential applications in industry.
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Affiliation(s)
- Ji-Dong Shen
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China.,Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou, P.R. China
| | - Xue Cai
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China.,Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou, P.R. China
| | - Zhi-Qiang Liu
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China.,Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou, P.R. China
| | - Yu-Guo Zheng
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China.,Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou, P.R. China
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4
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Sunder AV, Shah S, Rayavarapu P, Wangikar PP. Expanding the repertoire of nitrilases with broad substrate specificity and high substrate tolerance for biocatalytic applications. Process Biochem 2020. [DOI: 10.1016/j.procbio.2020.05.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Kumari P, Poddar R. Computational modeling for mutational analysis of nitrilase enzyme towards enhancement of binding empathy. J Biomol Struct Dyn 2020; 39:2289-2301. [PMID: 32216606 DOI: 10.1080/07391102.2020.1747546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Nitrilase enzyme (a green catalyst) is an industrially important enzyme which hydrolyses various nitrile compounds (containing -CN functional group) into amides and corresponding carboxylic acids. The current study explored the binding affinity and a method to enhance the catalysis activity of the enzyme using computational approaches. Four mutants were generated using sequential site-directed mutagenesis aiming that an increase in hydrogen bonds that will further increase binding efficiency towards the ligand. Molecular dynamics simulation was rigorously performed to check the stability of those mutants followed by docking to verify its interaction with the ligand. Various statistical dynamics analyses were performed to validate the structure. All the studies predict that built mutants are stable. Mutants 2 and 3 showed a better affinity towards acrylamide by forming the highest number of hydrogen bonds implying better catalysis. The binding affinity values of the Mutant 2 and Mutant 3 with acrylamide are -7.44 kcal/mol and -7.17 kcal/mol, respectively. This study may prove useful for the industry to develop efficient nitrilase enzymes with improved catalytic activity.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Priya Kumari
- Department of Bioengineering, Birla Institute of Technology-Mesra, Ranchi, JH, India
| | - Raju Poddar
- Department of Bioengineering, Birla Institute of Technology-Mesra, Ranchi, JH, India
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6
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A comparative multivariate analysis of nitrilase enzymes: An ensemble based computational approach. Comput Biol Chem 2019; 83:107095. [DOI: 10.1016/j.compbiolchem.2019.107095] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 06/20/2019] [Accepted: 07/11/2019] [Indexed: 12/20/2022]
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7
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Xue YP, Zhong HJ, Zou SP, Zheng YG. Efficient chemoenzymatic synthesis of gabapentin by control of immobilized biocatalyst activity in a stirred bioreactor. Biochem Eng J 2017. [DOI: 10.1016/j.bej.2017.06.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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8
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Xu JM, Cheng F, Fu FT, Hu HF, Zheng YG. Semi-Rational Engineering of Leucine Dehydrogenase for L-2-Aminobutyric Acid Production. Appl Biochem Biotechnol 2016; 182:898-909. [DOI: 10.1007/s12010-016-2369-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 12/12/2016] [Indexed: 11/29/2022]
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9
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Recent advances and challenges in the heterologous production of microbial nitrilases for biocatalytic applications. World J Microbiol Biotechnol 2016; 33:8. [DOI: 10.1007/s11274-016-2173-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 11/05/2016] [Indexed: 01/21/2023]
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10
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Li H, Dong W, Zhang Y, Liu K, Zhang W, Zhang M, Ma J, Jiang M. Enhanced catalytic efficiency of nitrilase from Acidovorax facilis 72W and application in bioconversion of 3-cyanopyridine to nicotinic acid. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.molcatb.2017.03.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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11
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Chen X, Liu ZQ, Lin CP, Zheng YG. Efficient biosynthesis of ethyl (R)-4-chloro-3-hydroxybutyrate using a stereoselective carbonyl reductase from Burkholderia gladioli. BMC Biotechnol 2016; 16:70. [PMID: 27756363 PMCID: PMC5070160 DOI: 10.1186/s12896-016-0301-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 10/13/2016] [Indexed: 12/25/2022] Open
Abstract
Background Ethyl (R)-4-chloro-3-hydroxybutyrate ((R)-CHBE) is a versatile chiral precursor for many pharmaceuticals. Although several biosynthesis strategies have been documented to convert ethyl 4-chloro-3-oxobutanoate (COBE) to (R)-CHBE, the catalytic efficiency and stereoselectivity are still too low to be scaled up for industrial applications. Due to the increasing demand of (R)-CHBE, it is essential to explore more robust biocatalyst capable of preparing (R)-CHBE efficiently. Results A stereoselective carbonyl reductase toolbox was constructed and employed into the asymmetric reduction of COBE to (R)-CHBE. A robust enzyme designed as BgADH3 from Burkholderia gladioli CCTCC M 2012379 exhibited excellent activity and enantioselectivity, and was further characterized and investigated in the asymmetric synthesis of (R)-CHBE. An economical and satisfactory enzyme-coupled cofactor recycling system was created using recombinant Escherichia coli cells co-expressing BgADH3 and glucose dehydrogenase genes to regenerate NADPH in situ. In an aqueous/octanol biphasic system, as much as 1200 mmol COBE was completely converted by using substrate fed-batch strategy to afford (R)-CHBE with 99.9 % ee at a space-time yield per gram of biomass of 4.47 mmol∙L−1∙h−1∙g DCW−1. Conclusions These data demonstrate the promising of BgADH3 in practical synthesis of (R)-CHBE as a valuable chiral synthon. This study allows for the further application of BgADH3 in the biosynthesis of chiral alcohols, and establishes a preparative scale process for producing (R)-CHBE with excellent enantiopurity. Electronic supplementary material The online version of this article (doi:10.1186/s12896-016-0301-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiang Chen
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014, China.,Engineering Research Center of Bioconversion and Biopurification of the Ministry of Education, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Zhi-Qiang Liu
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014, China.,Engineering Research Center of Bioconversion and Biopurification of the Ministry of Education, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Chao-Ping Lin
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014, China.,Engineering Research Center of Bioconversion and Biopurification of the Ministry of Education, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Yu-Guo Zheng
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014, China. .,Engineering Research Center of Bioconversion and Biopurification of the Ministry of Education, Zhejiang University of Technology, Hangzhou, 310014, China.
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12
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Chen X, Liu ZQ, Lin CP, Zheng YG. Chemoenzymatic synthesis of (S)-duloxetine using carbonyl reductase from Rhodosporidium toruloides. Bioorg Chem 2016; 65:82-9. [DOI: 10.1016/j.bioorg.2016.02.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Revised: 02/05/2016] [Accepted: 02/08/2016] [Indexed: 01/14/2023]
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Bioconversion of Iminodiacetonitrile to Iminodiacetic acid with whole cells of Lysinibacillus boronitolerans MTCC 107614 (IICT-akl252). Bioprocess Biosyst Eng 2016; 39:413-20. [PMID: 26742952 DOI: 10.1007/s00449-015-1524-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Accepted: 12/11/2015] [Indexed: 10/22/2022]
Abstract
Biotechnological potential of nitrilases are prompting significant interest in finding the novel microbes capable of hydrolyzing nitriles. In this view, we have screened about 450 bacterial strains for nitrilase production using bioconversion of iminodiacetonitrile (IDAN) to iminodiacetic acid (IDA) through hydrolysis and obtained six nitrilase-producing isolates. Among these six isolates, IICT-akl252 was promising which was identified as Lysinibacillus boronitolerans. This is the first report on L. boronitolerans for nitrilase activity. Optimization of various medium and reaction parameters for maximizing the nitrilase production using whole cells in shake flask was carried out for L. boronitolerans IICT-akl252. Sucrose (2 %) as a carbon source attained better nitrilase yield while IDAN appeared to be the preferable inducer (0.2 %). The maximum IDA formation was achieved with 100 mM IDAN and 150 mg/ml cells at 30 °C and pH 6.5. After optimization of the culture and reaction conditions, the activity of nitrilase was increased by 2.3-fold from 27.2 to 64.5 U. The enzyme was stable up to 1 h at 50 °C. The enzyme was able to hydrolyze aliphatic, aromatic and heterocyclic nitrile substrates.
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Gong JS, Li H, Lu ZM, Zhang XJ, Zhang Q, Yu JH, Zhou ZM, Shi JS, Xu ZH. Engineering of a fungal nitrilase for improving catalytic activity and reducing by-product formation in the absence of structural information. Catal Sci Technol 2016. [DOI: 10.1039/c5cy01535a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Semi-rational engineering approach was employed to improve the catalytic activity and reduce the by-product formation of fungal nitrilase.
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Affiliation(s)
- Jin-Song Gong
- School of Pharmaceutical Science
- Jiangnan University
- Wuxi 214122
- People's Republic of China
| | - Heng Li
- School of Pharmaceutical Science
- Jiangnan University
- Wuxi 214122
- People's Republic of China
| | - Zhen-Ming Lu
- School of Pharmaceutical Science
- Jiangnan University
- Wuxi 214122
- People's Republic of China
| | - Xiao-Juan Zhang
- School of Pharmaceutical Science
- Jiangnan University
- Wuxi 214122
- People's Republic of China
| | - Qiang Zhang
- School of Pharmaceutical Science
- Jiangnan University
- Wuxi 214122
- People's Republic of China
| | - Jiang-Hong Yu
- School of Pharmaceutical Science
- Jiangnan University
- Wuxi 214122
- People's Republic of China
| | - Zhe-Min Zhou
- The Key Laboratory of Industrial Biotechnology
- Ministry of Education
- Jiangnan University
- Wuxi 214122
- People's Republic of China
| | - Jin-Song Shi
- School of Pharmaceutical Science
- Jiangnan University
- Wuxi 214122
- People's Republic of China
| | - Zheng-Hong Xu
- School of Pharmaceutical Science
- Jiangnan University
- Wuxi 214122
- People's Republic of China
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Gong JS, Shi JS, Lu ZM, Li H, Zhou ZM, Xu ZH. Nitrile-converting enzymes as a tool to improve biocatalysis in organic synthesis: recent insights and promises. Crit Rev Biotechnol 2015; 37:69-81. [DOI: 10.3109/07388551.2015.1120704] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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16
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Su E, Lu C, Ma X, Cai W, Zhu S. High-level production ofArthrobacter aurescensCYC705 nitrilase inEscherichia colifor biosynthesis of iminodiacetic acid. Biotechnol Appl Biochem 2015; 63:564-71. [DOI: 10.1002/bab.1408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 06/16/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Erzheng Su
- Enzyme and Fermentation Technology Laboratory; College of Light Industry Science and Engineering; Nanjing Forestry University; Nanjing People's Republic of China
| | - Chao Lu
- Enzyme and Fermentation Technology Laboratory; College of Light Industry Science and Engineering; Nanjing Forestry University; Nanjing People's Republic of China
| | - Xiaoqiang Ma
- State Key Laboratory of Bioreactor Engineering; New World Institute of Biotechnology; East China University of Science and Technology; Shanghai People's Republic of China
| | - Wenwen Cai
- State Key Laboratory of Bioreactor Engineering; New World Institute of Biotechnology; East China University of Science and Technology; Shanghai People's Republic of China
| | - Shujing Zhu
- State Key Laboratory of Bioreactor Engineering; New World Institute of Biotechnology; East China University of Science and Technology; Shanghai People's Republic of China
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Cai W, Su E, Zhu S, Ren Y, Wei D. Characterization of a nitrilase from Arthrobacter aurescens CYC705 for synthesis of iminodiacetic acid. J GEN APPL MICROBIOL 2015; 60:207-14. [PMID: 25742970 DOI: 10.2323/jgam.60.207] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A nitrilase gene cyc705 from Arthrobacter aurescens CYC705 for synthesis of iminodiacetic acid (IDA) was cloned. This gene contained a 930 bp ORF, which encoded a polypeptide of 310 amino acids. A recombinant Escherichia coli BL21(DE3)/pET28a-cyc705 was constructed to achieve the heterologous expression of cyc705. This recombinant nitrilase was purified to homogeneity with a molecular weight of 36.7 kDa on SDS-PAGE and mass spectrometry, and characterized to be an oligomer of 14 subunits by gel permeation chromatography. Using iminodiacetonitrile (IDAN) as the substrate, the Vmax, Km, kcat and kcat/Km were 9.05 U mg(-1), 43.17 mM(-1), 94.1 min(-1) and 2.18×10(3) min(-1) M(-1), respectively. The optimum temperature and pH were 25°C and 5.8. The suitable substrates for the purified nitrilase were short-chain aliphatic dinitriles. High concentration of IDAN could be hydrolyzed to IDA in a shorter time.
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Affiliation(s)
- Wenwen Cai
- State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology
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Zhang XH, Liu ZQ, Xue YP, Zheng YG. Activity improvement of a regioselective nitrilase from Acidovorax facilis and its application in the production of 1-(cyanocyclohexyl) acetic acid. Process Biochem 2014. [DOI: 10.1016/j.procbio.2014.08.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Liu ZQ, Zhang XH, Xue YP, Xu M, Zheng YG. Improvement of Alcaligenes faecalis nitrilase by gene site saturation mutagenesis and its application in stereospecific biosynthesis of (R)-(-)-mandelic acid. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:4685-4694. [PMID: 24766313 DOI: 10.1021/jf405683f] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Nitrilases have recently received considerable attention as the biocatalysts for stereospecific production of carboxylic acids. To improve the activity, the nitrilase from Alcaligenes faecalis was selected for further modification by the gene site saturation mutagenesis method (GSSM), based on homology modeling and previous reports about mutations. After mutagenesis, the positive mutants were selected using a convenient two-step high-throughput screening method based on product formation and pH indicator combined with the HPLC method. After three rounds of GSSM, Mut3 (Gln196Ser/Ala284Ile) with the highest activity and ability of tolerance to the substrate was selected. As compared to the wild-type A. faecalis nitrilase, Mut3 showed 154% higher specific activity. Mut3 could retain 91.6% of its residual activity after incubation at pH 6.5 for 6 h. In a fed-batch reaction with 800 mM mandelonitrile as the substrate, the cumulative production of (R)-(-)-mandelic acid after 7.5 h of conversion reached 693 mM with an enantiomeric excess of 99%, and the space-time productivity of Mut3 was 21.50-fold higher than that of wild-type nitrilase. The Km, Vmax, and k(cat) of wild-type and Mut3 for mandelonitrile were 20.64 mM, 33.74 μmol mg(-1) min(-1), 24.45 s(-1), and 9.24 mM, 47.68 μmol mg(-1) min(-1), and 34.55 s(-1), respectively. A homology modeling and molecular docking study showed that the diameter of the catalytic tunnel of Mut3 became longer and that the tunnel volume was smaller. These structural changes are proposed to improve the hydrolytic activity and pH stability of Mut3. Mut3 has the potential for industrial applications in the upscale production of (R)-(-)-mandelic acid.
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Affiliation(s)
- Zhi-Qiang Liu
- Institute of Bioengineering, Zhejiang University of Technology , Hangzhou, Zhejiang 310014, People's Republic of China
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