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Jasińska A, Walaszczyk A, Paraszkiewicz K. Omics-Based Approaches in Research on Textile Dye Microbial Decolorization. Molecules 2024; 29:2771. [PMID: 38930836 PMCID: PMC11206425 DOI: 10.3390/molecules29122771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 06/02/2024] [Accepted: 06/07/2024] [Indexed: 06/28/2024] Open
Abstract
The development of the textile industry has negative effects on the natural environment. Cotton cultivation, dyeing fabrics, washing, and finishing require a lot of water and energy and use many chemicals. One of the most dangerous pollutants generated by the textile industry is dyes. Most of them are characterized by a complex chemical structure and an unfavorable impact on the environment. Especially azo dyes, whose decomposition by bacteria may lead to the formation of carcinogenic aromatic amines and raise a lot of concern. Using the metabolic potential of microorganisms that biodegrade dyes seems to be a promising solution for their elimination from contaminated environments. The development of omics sciences such as genomics, transcriptomics, proteomics, and metabolomics has allowed for a comprehensive approach to the processes occurring in cells. Especially multi-omics, which combines data from different biomolecular levels, providing an integrative understanding of the whole biodegradation process. Thanks to this, it is possible to elucidate the molecular basis of the mechanisms of dye biodegradation and to develop effective methods of bioremediation of dye-contaminated environments.
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Affiliation(s)
- Anna Jasińska
- Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Lodz, 90-237 Lodz, Poland;
| | - Aleksandra Walaszczyk
- Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, Doctoral School of Exact and Natural Sciences, University of Lodz, 90-237 Lodz, Poland;
| | - Katarzyna Paraszkiewicz
- Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Lodz, 90-237 Lodz, Poland;
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Purification and biochemical characterization of a new thermostable laccase from Enterococcus faecium A2 by a three-phase partitioning method and investigation of its decolorization potential. Arch Microbiol 2022; 204:533. [PMID: 35906438 DOI: 10.1007/s00203-022-03054-x] [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: 11/24/2021] [Revised: 06/02/2022] [Accepted: 06/03/2022] [Indexed: 11/02/2022]
Abstract
Three-phase partitioning (TPP) is a simple, fast, cost-effective, and highly efficient process that can be used in the purification of laccases. In this study, microorganisms with laccase activity were isolated from water samples collected from the Agri-Diyadin hot spring. The isolate with the highest laccase activity was found to be the A2 strain. As a result of molecular (16S rRNA sequence) and conventional (morphological, biochemical, and physiological) analyses, it was determined that the A2 isolate was 99% similar to Enterococcus faecium (Genbank number: MH424896). The laccase was purified to 4.9-fold with 110% recovery using the TPP. The molecular mass of the enzyme was found by SDS-PAGE to be 50.11 kDa. Optimum pH 6.0 and optimum temperature for laccase were determined as 80 °C. The laccase exhibited pH stability over a wide range (pH 3.0-9.0) and a high thermostability, retaining over 90% of its activity after 1 h of incubation at 20-90 °C. The laccase exhibited high thermostability, with a heat inactivation half-life of approximately 24 h at 80 °C. The enzyme remained highly stable in the presence of surfactants and increased its activity in the presence of organic solvents, Cr2+, Cu2+, and Ag+ metal ions. The Km, Vmax, kcat, and kcat/Km values of laccase for 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) substrate were 0.68 mM, 5.29 μmol mL-1 min-1, 110.2 s-1, and 162.1 s-1 mM-1, respectively.
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3
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Enzymatically triggered delignification through a novel stable laccase: A mixed in-silico /in-vitro exploration of a complex environmental microbiota. Int J Biol Macromol 2022; 211:328-341. [PMID: 35551951 DOI: 10.1016/j.ijbiomac.2022.05.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 04/20/2022] [Accepted: 05/05/2022] [Indexed: 11/23/2022]
Abstract
Laccases have been broadly applied as a multitasking biocatalyst in various industries, but their applications tend to be limited by easy deactivation, lack of adequate stability, and susceptibility under complex conditions. Identifying stable laccase as a green-biocatalyst is crucial for developing cost-effective biorefining processes. In this direction, we attempted in-silico screening a stable metagenome-derived laccase (PersiLac1) from tannery wastewater in a complex environment. The laccase exhibited high thermostability, retaining 53.19% activity after 180 min at 70 °C, and it was stable in a wide range of pH (4.0-9.0). After 33 days of storage at 50°C, pH 6.0, the enzyme retained 71.65% of its activity. Various metal ions, inhibitors, and organic solvents showed that PersiLac1 has a stable structure. The stable PersiLac1 could successfully remove lignin and phenolic from quinoa husk and rice straw. In the separate hydrolysis and fermentation process (SHF) after 72 h, hydrolysis was obtained 100% and 73.4% for quinoa husk and rice straw, and fermentation by the S. cerevisiae was be produced 41.46 g/L and 27.75g/L ethanol, respectively. Results signified that the novel lignin-degrading enzyme was confirmed to have great potential for industrial application as a green-biocatalyst based on enzymatically triggered to delignification and detoxify lignocellulosic biomass.
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Mutations in the coordination spheres of T1 Cu affect Cu 2+-activation of the laccase from Thermus thermophilus. Biochimie 2021; 182:228-237. [PMID: 33535124 DOI: 10.1016/j.biochi.2021.01.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 12/15/2020] [Accepted: 01/11/2021] [Indexed: 02/01/2023]
Abstract
Thermus thermophilus laccase belongs to the sub-class of multicopper oxidases that is activated by the extra binding of copper to a methionine-rich domain allowing an electron pathway from the substrate to the conventional first electron acceptor, the T1 Cu. In this work, two key amino acid residues in the 1st and 2nd coordination spheres of T1 Cu are mutated in view of tuning their redox potential and investigating their influence on copper-related activity. Evolution of the kinetic parameters after copper addition highlights that both mutations play a key role influencing the enzymatic activity in distinct unexpected ways. These results clearly indicate that the methionine rich domain is not the only actor in the cuprous oxidase activity of CueO-like enzymes.
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Zhou Q, Guo M, Ni K, Kerton FM. Construction of supramolecular laccase enzymes and understanding of catalytic dye degradation using multispectral and molecular docking approaches. REACT CHEM ENG 2021. [DOI: 10.1039/d1re00111f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A non-covalent supramolecular enzyme system which was successfully constructed by non-covalent interaction of enzyme with substrates analogs can effectively recognize and degrade 13 kinds of dyes.
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Affiliation(s)
- Qingteng Zhou
- College of Engineering, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China
| | - Ming Guo
- College of Engineering, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China
- College of Science, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China
| | - Kaijie Ni
- College of Science, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China
| | - Francesca M. Kerton
- Department of Chemistry, Memorial University of Newfoundland, St. John's, NL, Canada A1B 3X7
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6
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Bu T, Yang R, Zhang Y, Cai Y, Tang Z, Li C, Wu Q, Chen H. Improving decolorization of dyes by laccase from Bacillus licheniformis by random and site-directed mutagenesis. PeerJ 2020; 8:e10267. [PMID: 33240620 PMCID: PMC7666548 DOI: 10.7717/peerj.10267] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 10/07/2020] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Dye wastewater increases cancer risk in humans. For the treatment of dyestuffs, biodegradation has the advantages of economy, high efficiency, and environmental protection compared with traditional physical and chemical methods. Laccase is the best candidate for dye degradation because of its multiple substrates and pollution-free products. METHODS Here, we modified the laccase gene of Bacillus licheniformis by error-prone PCR and site-directed mutagenesis and expressed in E. coli. The protein was purified by His-tagged protein purification kit. We tested the enzymatic properties of wild type and mutant laccase by single factor test, and further evaluated the decolorization ability of laccase to acid violet, alphazurine A, and methyl orange by spectrophotometry. RESULTS Mutant laccase Lacep69and D500G were superior to wild type laccase in enzyme activity, stability, and decolorization ability. Moreover, the laccase D500G obtained by site-directed mutagenesis had higher enzyme activity in both, and the specific activity of the purified enzyme was as high as 426.13 U/mg. Also, D500G has a higher optimum temperature of 70 °C and temperature stability, while it has a more neutral pH 4.5 and pH stability. D500G had the maximum enzyme activity at a copper ion concentration of 12 mM. The results of decolorization experiments showed that D500G had a strong overall decolorization ability, with a lower decolorization rate of 18% for methyl orange and a higher decolorization rate of 78% for acid violet. CONCLUSION Compared with the wild type laccase, the enzyme activity of D500G was significantly increased. At the same time, it has obvious advantages in the decolorization effect of different dyes. Also, the advantages of temperature and pH stability increase its tolerance to the environment of dye wastewater.
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Affiliation(s)
- Tongliang Bu
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Rui Yang
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - YanJun Zhang
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Yuntao Cai
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Zizhong Tang
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Chenglei Li
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Qi Wu
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Hui Chen
- College of Life Science, Sichuan Agricultural University, Ya’an, China
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Wang J, Chang F, Tang X, Li W, Yin Q, Yang Y, Hu Y. Bacterial laccase of Anoxybacillus ayderensis SK3-4 from hot springs showing potential for industrial dye decolorization. ANN MICROBIOL 2020. [DOI: 10.1186/s13213-020-01593-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Introduction
Laccases are green biocatalysts that possess attractive for the treatment of resistant environmental pollutants and dye effluents.
Purpose
To exploit the laccase of Anoxybacillus ayderensis SK3-4 that possesses dye decolorization ability at room and higher temperature, we characterized the enzyme in considerable detail and investigated its ability to decolorize different dyes.
Results
A bacterial laccase gene designed as LacAn from Anoxybacillus ayderensis SK3-4 of hot springs was cloned and expressed in Escherichia coli. LacAn is a monomeric protein with a molecular weight of 29.8 kDa. The optimum pH and temperature for syringaldazine oxidation were 7.0 and 75 °C, respectively. LacAn was stable at pH values ranging from 6.5 to 8.5 above 65 °C. The enzyme activity was significantly enhanced by Cu2+ and Mg2+ but inhibited by Zn2+ and Fe2+. Furthermore, LacAn showed high decolorization capability toward five dyes (direct blue 6, acid black 1, direct green 6, direct black 19, and acid blue 93) in the absence of redox mediators. It also demonstrated a wide temperature range, and it can retain its high decolorization ability even at high temperatures.
Conclusions
These properties including better enzymatic properties and efficiency to decolorize dyes demonstrate that the bacterial laccase LacAn has potentials for further industrial applications.
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Hao J, Zhang W, Wang H, Ziya N, Luo Y, Jia P, Zhang G, Ng T. Purification and properties of a laccase from the mushroom Agaricus sinodeliciosus. Biotechnol Appl Biochem 2020; 68:297-306. [PMID: 32282952 DOI: 10.1002/bab.1926] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 01/30/2020] [Indexed: 11/06/2022]
Abstract
A homogeneous monomeric laccase (ASL) from Agaricus sinodeliciosus, with a molecular mass of 65 kDa, was isolated using ion-exchange chromatography (CM-cellulose and Q-Sepharose) and gel-filtration chromatography (Superdex 75). This laccase exhibited maximum activity at 50 °C and pH 5.0. Hg2+ and Cd2+ significantly inhibited its activity. The laccase displayed a Km value of 0.9 mM toward 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS). In addition to ABTS, ASL exhibited higher affinity toward o-toluidine and benzidine than other substrates. ASL is able to decolorize malachite green and Eriochrome black T.
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Affiliation(s)
- Jingzhe Hao
- Research Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Ulmqi, People's Republic of China.,State Key Laboratory for Agrobiotechnology and Department of Microbiology, China Agricultural University, Beijing, People's Republic of China
| | - Weiwei Zhang
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, People's Republic of China
| | - Hexiang Wang
- State Key Laboratory for Agrobiotechnology and Department of Microbiology, China Agricultural University, Beijing, People's Republic of China
| | - Nur Ziya
- Research Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Ulmqi, People's Republic of China
| | - Ying Luo
- Research Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Ulmqi, People's Republic of China
| | - Peisong Jia
- Research Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Ulmqi, People's Republic of China
| | - Guoqing Zhang
- Beijing Key Laboratory for Agricultural Application and New Technique, College of Plant Science and Technology, Beijing University of Agriculture, Beijing, People's Republic of China
| | - Tzibun Ng
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, People's Republic of China
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9
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Mohit E, Tabarzad M, Faramarzi MA. Biomedical and Pharmaceutical-Related Applications of Laccases. Curr Protein Pept Sci 2020; 21:78-98. [DOI: 10.2174/1389203720666191011105624] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 08/17/2019] [Accepted: 08/21/2019] [Indexed: 12/07/2022]
Abstract
The oxidation of a vast range of phenolic and non-phenolic substrates has been catalyzed by
laccases. Given a wide range of substrates, laccases can be applied in different biotechnological applications.
The present review was conducted to provide a broad context in pharmaceutical- and biomedical-
related applications of laccases for academic and industrial researchers. First, an overview of biological
roles of laccases was presented. Furthermore, laccase-mediated strategies for imparting antimicrobial
and antioxidant properties to different surfaces were discussed. In this review, laccase-mediated
mechanisms for endowing antimicrobial properties were divided into laccase-mediated bio-grafting of
phenolic compounds on lignocellulosic fiber, chitosan and catheters, and laccase-catalyzed iodination.
Accordingly, a special emphasis was placed on laccase-mediated functionalization for creating antimicrobials,
particularly chitosan-based wound dressings. Additionally, oxidative bio-grafting and oxidative
polymerization were described as the two main laccase-catalyzed reactions for imparting antioxidant
properties. Recent laccase-related studies were also summarized regarding the synthesis of antibacterial
and antiproliferative agents and the degradation of pharmaceuticals and personal care products.
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Affiliation(s)
- Elham Mohit
- Department of Pharmaceutical Biotechnology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Tabarzad
- Protein Technology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Ali Faramarzi
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tehran University of Medical Sciences, P.O. Box 14155-6451, Tehran 1417614411, Iran
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10
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Abd El-Rahim WM, Abdel Azeiz AZ, Moawad H, Sadowsky MJ. Identification and characterization of two peroxidases from Lichtheimia corymbifera. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2019. [DOI: 10.1016/j.bcab.2019.01.033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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11
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Yang Q, Zhang M, Zhang M, Wang C, Liu Y, Fan X, Li H. Characterization of a Novel, Cold-Adapted, and Thermostable Laccase-Like Enzyme With High Tolerance for Organic Solvents and Salt and Potent Dye Decolorization Ability, Derived From a Marine Metagenomic Library. Front Microbiol 2018; 9:2998. [PMID: 30568647 PMCID: PMC6290062 DOI: 10.3389/fmicb.2018.02998] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 11/20/2018] [Indexed: 11/13/2022] Open
Abstract
Synthetic dyes are widely used in many industries, but they cause serious environmental problems due to their carcinogenic and mutagenic properties. In contrast to traditional physical and chemical treatments, biodegradation is generally considered an environmental-friendly, efficient, and inexpensive way to eliminate dye contaminants. Here, a novel laccase-like enzyme Lac1326 was cloned from a marine metagenomic library. It showed a maximum activity at 60°C, and it retained more than 40% of its maximal activity at 10°C and more than 50% at 20-70°C. Interestingly, the laccase behaved stably below 50°C, even in commonly used water-miscible organic solvents. The enzyme decolorized all tested dyes with high decolorization efficiency. This thermostable enzyme with high decolorization activity and excellent tolerance of organic solvents and salt has remarkable potential for bioremediation of dye wastewater. It is thus proposed as an industrial enzyme.
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Affiliation(s)
- Qihao Yang
- School of Basic Courses, Guangdong Pharmaceutical University, Guangzhou, China
| | - Mengle Zhang
- School of Basic Courses, Guangdong Pharmaceutical University, Guangzhou, China
| | - Manman Zhang
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Chunqing Wang
- School of Basic Courses, Guangdong Pharmaceutical University, Guangzhou, China
| | - Yanyan Liu
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Xinjiong Fan
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - He Li
- School of Basic Courses, Guangdong Pharmaceutical University, Guangzhou, China
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Improving the catalytic efficiency of Bacillus pumilus CotA-laccase by site-directed mutagenesis. Appl Microbiol Biotechnol 2016; 101:1935-1944. [DOI: 10.1007/s00253-016-7962-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/10/2016] [Accepted: 10/24/2016] [Indexed: 10/20/2022]
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High Laccase Expression by Trametes versicolor in a Simulated Textile Effluent with Different Carbon Sources and PHs. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2016; 13:ijerph13080778. [PMID: 27490563 PMCID: PMC4997464 DOI: 10.3390/ijerph13080778] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 07/26/2016] [Accepted: 07/28/2016] [Indexed: 12/03/2022]
Abstract
Textile effluents are highly polluting and have variable and complex compositions. They can be extremely complex, with high salt concentrations and alkaline pHs. A fixed-bed bioreactor was used in the present study to simulate a textile effluent treatment, where the white-rot fungus, Trametes versicolor, efficiently decolourised the azo dye Reactive Black 5 over 28 days. This occurred under high alkaline conditions, which is unusual, but advantageous, for successful decolourisation processes. Active dye decolourisation was maintained by operation in continuous culture. Colour was eliminated during the course of operation and maximum laccase (Lcc) activity (80.2 U∙L−1) was detected after glycerol addition to the bioreactor. Lcc2 gene expression was evaluated with different carbon sources and pH values based on reverse transcriptase-PCR (polymerase chain reaction). Glycerol was shown to promote the highest lcc2 expression at pH 5.5, followed by sucrose and then glucose. The highest levels of expression occurred between three and four days, which corroborate the maximum Lcc activity observed for sucrose and glycerol on the bioreactor. These results give new insights into the use of T. versicolor in textile dye wastewater treatment with high pHs.
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14
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Laccase engineering: From rational design to directed evolution. Biotechnol Adv 2015; 33:25-40. [DOI: 10.1016/j.biotechadv.2014.12.007] [Citation(s) in RCA: 168] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Revised: 12/17/2014] [Accepted: 12/21/2014] [Indexed: 10/24/2022]
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15
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Structural insights into 2,2'-azino-Bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)-mediated degradation of reactive blue 21 by engineered Cyathus bulleri Laccase and characterization of degradation products. Appl Environ Microbiol 2014; 80:7484-95. [PMID: 25261507 DOI: 10.1128/aem.02665-14] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Advanced oxidation processes are currently used for the treatment of different reactive dyes which involve use of toxic catalysts. Peroxidases are reported to be effective on such dyes and require hydrogen peroxide and/or metal ions. Cyathus bulleri laccase, expressed in Pichia pastoris, catalyzes efficient degradation (78 to 85%) of reactive azo dyes (reactive black 5, reactive orange 16, and reactive red 198) in the presence of synthetic mediator ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)]. This laccase was engineered to degrade effectively reactive blue 21 (RB21), a phthalocyanine dye reported to be decolorized only by peroxidases. The 816-bp segment (toward the C terminus) of the lcc gene was subjected to random mutagenesis and enzyme variants (Lcc35, Lcc61, and Lcc62) were selected based on increased ABTS oxidizing ability. Around 78 to 95% decolorization of RB21 was observed with the ABTS-supplemented Lcc variants in 30 min. Analysis of the degradation products by mass spectrometry indicated the formation of several low-molecular-weight compounds. Mapping the mutations on the modeled structure implicated residues both near and far from the T1 Cu site that affected the catalytic efficiency of the mutant enzymes on ABTS and, in turn, the rate of oxidation of RB21. Several inactive clones were also mapped. The importance of geometry as well as electronic changes on the reactivity of laccases was indicated.
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16
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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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17
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Abdellaoui S, Noiriel A, Henkens R, Bonaventura C, Blum LJ, Doumèche B. A 96-well electrochemical method for the screening of enzymatic activities. Anal Chem 2013; 85:3690-7. [PMID: 23461701 DOI: 10.1021/ac303777r] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The rapid electrochemical screening of enzyme activities in bioelectronics is still a challenging issue. In order to solve this problem, we propose to use a 96-well electrochemical assay. This system is composed of 96 screen-printed electrodes on a printed circuit board adapted from a commercial system (carbon is used as the working electrode and silver chloride as the counter/reference electrode). The associated device allows for the measurements on the 96 electrodes to be performed within a few seconds. In this work, we demonstrate the validity of the screening method with the commercial laccase from the fungus Trametes versicolor. The signal-to-noise ratio (S/N) is found to be the best way to analyze the electrochemical signals. The S/N follows a saturation-like mechanism with a dynamic linear range of two decades ranging from 0.5 to 75 ng of laccase (corresponding to enzymatic activities from 62 × 10(-6) to 9.37 × 10(-3) μmol min(-1)) and a sensitivity of 3027 μg(-1) at +100 mV versus Ag/AgCl. Laccase inhibitors (azide and fluoride anions), pH optima, and interfering molecules could also be identified within a few minutes.
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Affiliation(s)
- Sofiène Abdellaoui
- GEMBAS (Génie Enzymatique, Membranes Biomimétiques et Assemblages Supramoléculaires), ICBMS UMR 5246, Université Lyon 1, CNRS, INSA Lyon, Villeurbanne, France
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Production of L-ribose from L-ribulose by a triple-site variant of mannose-6-phosphate isomerase from Geobacillus thermodenitrificans. Appl Environ Microbiol 2012; 78:3880-4. [PMID: 22447612 DOI: 10.1128/aem.07012-11] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A triple-site variant (W17Q N90A L129F) of mannose-6-phosphate isomerase from Geobacillus thermodenitrificans was obtained by combining variants with residue substitutions at different positions after random and site-directed mutagenesis. The specific activity and catalytic efficiency (k(cat)/K(m)) for L-ribulose isomerization of this variant were 3.1- and 7.1-fold higher, respectively, than those of the wild-type enzyme at pH 7.0 and 70°C in the presence of 1 mM Co(2+). The triple-site variant produced 213 g/liter l-ribose from 300 g/liter L-ribulose for 60 min, with a volumetric productivity of 213 g liter(-1) h(-1), which was 4.5-fold higher than that of the wild-type enzyme. The k(cat)/K(m) and productivity of the triple-site variant were approximately 2-fold higher than those of the Thermus thermophilus R142N variant of mannose-6-phosphate isomerase, which exhibited the highest values previously reported.
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