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Sharma V, Pugazhenthi G, Vasanth D. Production and characterization of a novel thermostable laccase from Bacillus licheniformis VNQ and its application in synthesis of bioactive 1,4-naphthoquinones. J Biosci Bioeng 2021; 133:8-16. [PMID: 34629297 DOI: 10.1016/j.jbiosc.2021.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 08/30/2021] [Accepted: 09/11/2021] [Indexed: 10/20/2022]
Abstract
Bacterial laccases have proven to be a potential biocatalyst for various industrial applications due to their remarkable catalytic and stability properties. In this study, a novel thermostable laccase was produced from the bacterium Bacillus licheniformis VNQ by submerged fermentation. The specific activity of crude and purified laccase was found to be 13.17 U mg-1 and 83.47 U mg-1, respectively. The enzyme possessed a molecular mass of ∼48 kDa when characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The optimum temperature and pH for enzyme activity was determined to be 55°C and 5.0, respectively. The enzyme was considered to be thermo-tolerant as it possessed a half-life of 4 h at 70°C. The enzyme was utilized for the oxidative biotransformation of in situ synthesized p-quinones to biologically active compounds, 1,4-naphthoquinone and its derivative. The obtained products were characterized using nuclear magnetic resonance (NMR) spectroscopy and gas chromatography-mass spectrometry (GC-MS) analysis. A high yield of naphthoquinones (74.93 ± 1.2%) with 1,4-naphthoquinone (60.61 ± 1.0%), and its derivative 2-hydroxy-1,4-naphthoquinone (14.32 ± 0.2%) was obtained at the optimized reaction conditions.
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Affiliation(s)
- Vikas Sharma
- Department of Biotechnology, National Institute of Technology Raipur, Raipur, Chhattisgarh 492010, India
| | - Gopal Pugazhenthi
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Dhakshinamoorthy Vasanth
- Department of Biotechnology, National Institute of Technology Raipur, Raipur, Chhattisgarh 492010, India.
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Wu MH, Lin MC, Lee CC, Yu SM, Wang AHJ, Ho THD. Enhancement of laccase activity by pre-incubation with organic solvents. Sci Rep 2019; 9:9754. [PMID: 31278318 PMCID: PMC6611822 DOI: 10.1038/s41598-019-45118-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 05/23/2019] [Indexed: 11/09/2022] Open
Abstract
Laccases that are tolerant to organic solvents are powerful bio-catalysts with broad applications in biotechnology. Most of these uses must be accomplished at high concentration of organic solvents, during which proteins undergo unfolding, thereby losing enzyme activity. Here we show that organic-solvent pre-incubation provides effective and reversible 1.5- to 4.0-fold enhancement of enzyme activity of fungal laccases. Several organic solvents, including acetone, methanol, ethanol, DMSO, and DMF had an enhancement effect among all laccases studied. The enhancement was not substrate-specific and could be observed by using both phenolic and non-phenolic substrates. Laccase preincubated with organic solvents was sensitive to high temperature but remained stable at 25 °C, for an advantage for long-term storage. The acetone-pre-incubated 3-D structure of DLac, a high-efficiency fungal laccase, was determined and confirmed that the DLac protein structure remains intact and stable at a high concentration of organic solvent. Moreover, the turnover rates of fungal laccases were improved after organic-solvent pre-incubation, with DLac showing the highest enhancement among the fungal laccases examined. Our investigation sheds light on improving fungal laccase usage under extreme conditions and extends opportunities for bioremediation, decolorization, and organic synthesis.
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Affiliation(s)
- Meng-Hsuan Wu
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan, ROC.,Department of Life Sciences, National Cheng Kung University, Tainan, 701, Taiwan, ROC
| | - Meng-Chun Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan, ROC
| | - Cheng-Chung Lee
- Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan, ROC
| | - Su-May Yu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC.,Agricultural Biotechnology Center, National Chung Hsing University, Taichung, 402, Taiwan, ROC.,Department of Life Sciences, National Chung Hsing University, Taichung, 402, Taiwan, ROC
| | - Andrew H-J Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan, ROC
| | - Tuan-Hua David Ho
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan, ROC. .,Agricultural Biotechnology Center, National Chung Hsing University, Taichung, 402, Taiwan, ROC. .,Department of Life Sciences, National Chung Hsing University, Taichung, 402, Taiwan, ROC.
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Zhang M, Zhang M, Liu Y, Chen Y, Zhang K, Wang C, Zhao X, Zhou C, Gao J, Xie X, Zheng D, Zhao G. DFT/TDDFT theoretical investigation on the excited-state intermolecular hydrogen bonding interactions, photoinduced charge transfer, and vibrational spectroscopic properties of deprotonated deoxyadenosine monophosphate [dAMP-H] − anion in aqueous solution: Upon photoexcitation of hydrogen-bonded model complexes [dAMP-H] − –nH 2 O ( n = 0, 1, 2, 3, 4). J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.07.120] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Jia H, Gao Z, Ma Y, Zhong C, Wang C, Zhou H, Wei P. Preparation and characterization of a highly stable phenoxazinone synthase nanogel. Chem Cent J 2016; 10:34. [PMID: 27239225 PMCID: PMC4884384 DOI: 10.1186/s13065-016-0178-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 05/10/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Phenoxazinone synthase (PHS) is a laccase-like multicopper oxidase originating from Streptomyces with great industrial application potential. In this paper, we prepared the PHS nanogel retaining 82 % of its initial activity by aqueous in situ polymerization at pH 9.3. RESULTS The average diameter of the PHS nanogel was 50.8 nm based on dynamic light scattering (DLS) analysis. Fluorescence analysis indicated the impressive preservation of the enzyme molecular structure upon modification. The PHS nanogel exhibited the most activity at pH 4.0-4.5 and 50 °C while the corresponding values were pH 4.5 and 40 °C for the native PHS. The K m and V max of the PHS nanogel were found to be 0.052 mM and 0.018 mM/min, whereas those of the native PHS were 0.077 mM and 0.021 mM/min, respectively. In addition, the PHS nanogel possessed higher thermal and storage stability and solvent tolerance compared with the native one. The half-life of the PHS nanogel was 1.71 h and multiplied around ninefold compared to 0.19 h for the native one. CONCLUSION In summary, the PHS nanogel could be a promising biocatalyst in industry.
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Affiliation(s)
- Honghua Jia
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800 China
| | - Zhen Gao
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800 China
| | - Yingying Ma
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800 China
| | - Chao Zhong
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800 China
| | - Chunming Wang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800 China
| | - Hua Zhou
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800 China
| | - Ping Wei
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800 China
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Zhang X, Hua M, Lv L, Pan B. Ionic polymer-coated laccase with high activity and enhanced stability: application in the decolourisation of water containing AO7. Sci Rep 2015; 5:8253. [PMID: 25652843 PMCID: PMC4317704 DOI: 10.1038/srep08253] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 01/12/2015] [Indexed: 12/29/2022] Open
Abstract
Eliminating dyes in environmental water purification remains a formidable challenge. Laccase is a unique, environmentally friendly and efficient biocatalyst that can degrade pollutants. However, the use of laccase for the degradation of pollutants is considerably limited by its susceptibility to environmental changes and its poor reusability. We fabricated a novel biocatalyst (LacPG) by coating polyethylenimine onto the native laccase (Lac) followed by crosslinking with glutaraldehyde. The stability of the resulting LacPG was highly enhanced against pH variations, thermal treatments and provided better long-term storage with a negligible loss in enzymatic activity. Compared to Lac, LacPG exhibited significantly higher decolourisation efficiency in the degradation of a representative azo dye, acid orange 7 (AO7), which resulted from the electrostatic attraction between the coating and AO7. LacPG was separated from the AO7 solution using an ultrafiltration unit. The increased size and modified surface chemistry of LacPG facilitated ultrafiltration and reduced membrane fouling. LacPG exhibited enhanced stability, high catalytic activity and favourable properties for membrane separation; therefore, LacPG could be continuously reused in an enzymatic membrane reactor with a high efficiency for decolourising water containing AO7. The developed strategy appears to be promising for enhancing the applicability of laccase in practical water treatment.
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Affiliation(s)
- Xiaolin Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P.R. China
| | - Ming Hua
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P.R. China
| | - Lu Lv
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P.R. China
| | - Bingcai Pan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P.R. China
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Brander S, Mikkelsen JD, Kepp KP. Characterization of an alkali- and halide-resistant laccase expressed in E. coli: CotA from Bacillus clausii. PLoS One 2014; 9:e99402. [PMID: 24915287 PMCID: PMC4051777 DOI: 10.1371/journal.pone.0099402] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 05/13/2014] [Indexed: 01/25/2023] Open
Abstract
The limitations of fungal laccases at higher pH and salt concentrations have intensified the search for new extremophilic bacterial laccases. We report the cloning, expression, and characterization of the bacterial cotA from Bacillus clausii, a supposed alkalophilic ortholog of cotA from B. subtilis. Both laccases were expressed in E. coli strain BL21(DE3) and characterized fully in parallel for strict benchmarking. We report activity on ABTS, SGZ, DMP, caffeic acid, promazine, phenyl hydrazine, tannic acid, and bilirubin at variable pH. Whereas ABTS, promazine, and phenyl hydrazine activities vs. pH were similar, the activity of B. clausii cotA was shifted upwards by ∼0.5–2 pH units for the simple phenolic substrates DMP, SGZ, and caffeic acid. This shift is not due to substrate affinity (KM) but to pH dependence of catalytic turnover: The kcat of B. clausii cotA was 1 s−1 at pH 6 and 5 s−1 at pH 8 in contrast to 6 s−1 at pH 6 and 2 s−1 at pH 8 for of B. subtilis cotA. Overall, kcat/KM was 10-fold higher for B. subtilis cotA at pHopt. While both proteins were heat activated, activation increased with pH and was larger in cotA from B. clausii. NaCl inhibited activity at acidic pH, but not up to 500–700 mM NaCl in alkaline pH, a further advantage of the alkali regime in laccase applications. The B. clausii cotA had ∼20 minutes half-life at 80°C, less than the ∼50 minutes at 80°C for cotA from B. subtilis. While cotA from B. subtilis had optimal stability at pH∼8, the cotA from B. clausii displayed higher combined salt- and alkali-resistance. This resistance is possibly caused by two substitutions (S427Q and V110E) that could repel anions to reduce anion-copper interactions at the expense of catalytic proficiency, a trade-off of potential relevance to laccase optimization.
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Affiliation(s)
- Søren Brander
- Technical University of Denmark, DTU Chemical Engineering, Kongens Lyngby, Denmark
- Technical University of Denmark, DTU Chemistry, Kongens Lyngby, Denmark
| | - Jørn D. Mikkelsen
- Technical University of Denmark, DTU Chemical Engineering, Kongens Lyngby, Denmark
| | - Kasper P. Kepp
- Technical University of Denmark, DTU Chemistry, Kongens Lyngby, Denmark
- * E-mail:
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Affiliation(s)
- Ghanshyam S Chauhan
- Department of Chemistry; Himachal Pradesh University; Summer Hill Shimla 171005 India
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