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Towards robust Pseudomonas cell factories to harbour novel biosynthetic pathways. Essays Biochem 2021; 65:319-336. [PMID: 34223620 PMCID: PMC8314020 DOI: 10.1042/ebc20200173] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 05/01/2021] [Accepted: 05/24/2021] [Indexed: 02/07/2023]
Abstract
Biotechnological production in bacteria enables access to numerous valuable chemical compounds. Nowadays, advanced molecular genetic toolsets, enzyme engineering as well as the combinatorial use of biocatalysts, pathways, and circuits even bring new-to-nature compounds within reach. However, the associated substrates and biosynthetic products often cause severe chemical stress to the bacterial hosts. Species of the Pseudomonas clade thus represent especially valuable chassis as they are endowed with multiple stress response mechanisms, which allow them to cope with a variety of harmful chemicals. A built-in cell envelope stress response enables fast adaptations that sustain membrane integrity under adverse conditions. Further, effective export machineries can prevent intracellular accumulation of diverse harmful compounds. Finally, toxic chemicals such as reactive aldehydes can be eliminated by oxidation and stress-induced damage can be recovered. Exploiting and engineering these features will be essential to support an effective production of natural compounds and new chemicals. In this article, we therefore discuss major resistance strategies of Pseudomonads along with approaches pursued for their targeted exploitation and engineering in a biotechnological context. We further highlight strategies for the identification of yet unknown tolerance-associated genes and their utilisation for engineering next-generation chassis and finally discuss effective measures for pathway fine-tuning to establish stable cell factories for the effective production of natural compounds and novel biochemicals.
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Davis R, Molloy S, Quigley B, Nikodinovic-Runic J, Solano F, O'Connor KE. Biocatalytic versatility of engineered and wild-type tyrosinase from R. solanacearum for the synthesis of 4-halocatechols. Appl Microbiol Biotechnol 2018; 102:5121-5131. [PMID: 29691629 DOI: 10.1007/s00253-018-8994-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 04/03/2018] [Accepted: 04/06/2018] [Indexed: 10/17/2022]
Abstract
We evaluated the kinetic characteristics of wild type (WT) and three engineered variants (RVC10, RV145, and C10_N322S) of tyrosinase from Ralstonia solanacearum and their potential as biocatalysts to produce halogenated catechols. RV145 exhibited a 3.6- to 14.5-fold improvement in catalytic efficiency (kcat/Km) with both reductions in Km and increases in kcat compared to WT, making it the best R. solanacearum tyrosinase variant towards halogenated phenols. RVC10 also exhibited increases in catalytic efficiency with all the tested phenols. A single-mutation variant (C10_N322S) exhibited the greatest improvement in kcat but lowest improvement in catalytic efficiency due to an increase in Km compared to WT. Consistent with kinetic characteristics, biotransformation experiments showed that RV145 was a superior biocatalyst in comparison to WT. To prevent through conversion of the catechol to quinone, ascorbic acid (AA) was added to the biotransformation medium in 1:2 (substrate:AA) ratio resulting in a catechol yield of > 90%. Flask experiments with 10 mM 4-iodophenol and 10 μg/mL of the RV145 enzyme yielded 9.5 mM 4-iodocatechol in the presence of 20 mM AA in 30 min. Similarly, 10 mM 4-fluorophenol was completely consumed by 20 μg/mL of RV145 enzyme and yielded 9.2 mM 4-fluorocatechol in the presence of 20 mM AA in 80 min. The biotransformation of 20 mM 4-fluorphenol was incomplete (93%) and the yield of 4-flurocatechol was 87.5%. The 4-halophenol conversion rates and product yields obtained in this study are the highest reported using tyrosinase or any other enzyme.
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Affiliation(s)
- Reeta Davis
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Susan Molloy
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Blathnaid Quigley
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Jasmina Nikodinovic-Runic
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland.,Institute for Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, Belgrade, 11000, Serbia
| | - Francisco Solano
- Department of Biochemistry and Molecular Biology B and Immunology, University of Murcia, Murcia, Spain
| | - Kevin E O'Connor
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland.
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Brooks SJ, Nikodinovic J, Martin L, Doyle EM, O'Sullivan T, Guiry PJ, Coulombel L, Li Z, O'Connor KE. Production of a chiral alcohol, 1-(3,4-dihydroxyphenyl) ethanol, by mushroom tyrosinase. Biotechnol Lett 2013; 35:779-83. [PMID: 23355036 DOI: 10.1007/s10529-013-1148-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Accepted: 01/10/2013] [Indexed: 11/28/2022]
Abstract
1-(3,4-Dihydroxyphenyl) ethanol was produced biocatalytically for the first time using mushroom tyrosinase. 4-Ethylphenol at 1 mM was consumed over 12 min giving 0.23 mM 4-ethylcatechol and 0.36 mM (R/S)-1-(3,4-dihydroxyphenyl) ethanol (ee 0.5 %). Mushroom tyrosinase consumed 4-ethylphenol at 6.7 μmol min(-1) mg protein(-1) while the rates of formation of 4-ethylcatechol and 1-(3,4-dihydroxyphenyl) ethanol were 1.1 and 1.9 μmol min(-1) mg protein(-1). Addition of the ascorbic acid, as a reducing agent to biotransformation reactions, increased 4-ethylcatechol formation by 340 %. However, accumulation of 1-(3,4-dihydroxyphenyl) ethanol was not observed in the presence of ascorbic acid. While the 1-(3,4-dihydroxyphenyl) ethanol was racemic, it is the first chiral product produced by tyrosinase starting from a non-chiral substrate.
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Affiliation(s)
- Sarah J Brooks
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland.
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Fairhead M, Thöny-Meyer L. Bacterial tyrosinases: old enzymes with new relevance to biotechnology. N Biotechnol 2011; 29:183-91. [PMID: 21664502 DOI: 10.1016/j.nbt.2011.05.007] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 05/20/2011] [Accepted: 05/20/2011] [Indexed: 10/18/2022]
Abstract
Tyrosinases are copper-containing dioxygen activating enzymes found in many species of bacteria and are usually associated with melanin production. These proteins have a strong preference for phenolic and diphenolic substrates and are somewhat limited in their reaction scope, always producing an activated quinone as product. Despite this fact they have potential in several biotechnological applications, including the production of novel mixed melanins, protein cross-linking, phenolic biosensors, production of l-DOPA, phenol and dye removal and biocatalysis. Although most studies have used Streptomyces sp. enzymes, there are several other examples of these proteins that are also of potential interest. For instance a solvent tolerant enzyme has been described, as well as an enzyme with both tyrosinase and laccase activities, enzymes with altered substrate preferences, an enzyme produced as an inactive zymogen as well as examples which do not require auxiliary proteins for copper insertion (unlike the Streptomyces sp. enzymes which do require such a protein). This article will summarise the reports on the biotechnological applications of bacterial tyrosinases as well as the current information available on the different types of this enzyme.
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Affiliation(s)
- Michael Fairhead
- EMPA, Swiss Federal Laboratories for Materials Testing and Research, Laboratory for Biomaterials, Lerchenfeldstrasse 5, St. Gallen, CH-9014, Switzerland
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Coulombel L, Nolan LC, Nikodinovic J, Doyle EM, O’Connor KE. Biotransformation of 4-halophenols to 4-halocatechols using Escherichia coli expressing 4-hydroxyphenylacetate 3-hydroxylase. Appl Microbiol Biotechnol 2010; 89:1867-75. [DOI: 10.1007/s00253-010-2969-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 10/19/2010] [Accepted: 10/19/2010] [Indexed: 10/18/2022]
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Biodegradation of polyfluorinated biphenyl in bacteria. Biodegradation 2010; 22:741-9. [DOI: 10.1007/s10532-010-9411-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Accepted: 08/23/2010] [Indexed: 10/19/2022]
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Nikodinovic-Runic J, Martin LB, Babu R, Blau W, O'Connor KE. Characterization of melanin-overproducing transposon mutants of Pseudomonas putida F6. FEMS Microbiol Lett 2009; 298:174-83. [PMID: 19624744 DOI: 10.1111/j.1574-6968.2009.01716.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Two melanin-overproducing Pseudomonas putida F6 mutants were generated using transposon (Tn5) mutagenesis. Mutants were disrupted in a transcriptional regulator (TR) and a homogentisate 1,2-dioxygenase (HDO) gene. Colonies of mutant F6-TR overproduced a black pigment on solid medium. The same mutant (F6-TR) had a 3.7-fold higher tyrosinase activity compared with the wild-type strain when induced with ferulic acid. However in tyrosine uptake assays whole cells of the mutant strain F6-TR consumed eight times less tyrosine compared with the wild-type strain. Mutant F6-HDO produced a diffusible red pigment into the growth medium. Pigment production by mutant F6-HDO is sixfold higher than the wild-type strain. The biomass yield of mutant F6-HDO grown on tyrosine as the sole source of carbon and energy was 1.2-fold lower than the wild-type strain. While the growth of the wild-type strain was completely inhibited by 5 min of exposure to UV light (254 nm) both mutant strains showed survival rates >30%. Mutant F6-HDO was able to tolerate higher concentrations of hydrogen peroxide (H(2)O(2)) exhibiting 1.5 times smaller zones of inhibition at 10 mM H(2)O(2) compared with mutant F6-TR and the wild-type strain. The pigments produced by all strains were purified and confirmed to be melanins.
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Martin LB, Nikodinovic J, Mc Mahon AM, Vijgenboom E, O’Connor KE. Assessing the catalytic activity of three different sources of tyrosinase: A study of the oxidation of mono- and difluorinated monophenols. Enzyme Microb Technol 2008. [DOI: 10.1016/j.enzmictec.2008.03.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Nolan LC, O'Connor KE. Dioxygenase- and monooxygenase-catalysed synthesis of cis-dihydrodiols, catechols, epoxides and other oxygenated products. Biotechnol Lett 2008; 30:1879-91. [PMID: 18612597 DOI: 10.1007/s10529-008-9791-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2008] [Revised: 06/20/2008] [Accepted: 06/24/2008] [Indexed: 11/29/2022]
Affiliation(s)
- Louise C Nolan
- School of Biomolecular and Biomedical Science, Centre for Synthesis and Chemical Biology, Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
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Vaidya BK, Karale AJ, Suthar HK, Ingavle G, Pathak TS, Ponrathnam S, Nene S. Immobilization of mushroom polyphenol oxidase on poly(allyl glycidyl ether-co-ethylene glycol dimethacrylate) macroporous beaded copolymers. REACT FUNCT POLYM 2007. [DOI: 10.1016/j.reactfunctpolym.2007.05.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Murphy CD. The Application of19F Nuclear Magnetic Resonance to Investigate Microbial Biotransformations of Organofluorine Compounds. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2007; 11:314-24. [PMID: 17883342 DOI: 10.1089/omi.2007.0002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Fluorinated organic compounds, although rare in nature, are significant environmental contaminants owing to the numerous applications for which this class of compounds is employed. It is important that biodegradation of these compounds can be readily assessed in order to provide information on their fate in the environment. Fluorine-19 nuclear magnetic resonance (19F NMR) spectroscopy has emerged as a very useful technique to readily determine the catabolism of fluorinated aromatic compounds by microorganisms, either in whole cell or cell-free systems. The principal advantage of this technique is that fluorinated compounds can be observed directly in the culture supernatant or enzyme assay, without purification or derivatization. In this review an account of the application of 19F NMR in the study of microbial metabolism of organofluorine compounds is presented.
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Affiliation(s)
- Cormac D Murphy
- School of Biomolecular and Biomedical Science, Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin, Ireland.
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Nolan LC, O'Connor KE. Use of Pseudomonas mendocina, or recombinant Escherichia coli cells expressing toluene-4-monooxygenase, and a cell-free tyrosinase for the synthesis of 4-fluorocatechol from fluorobenzene. Biotechnol Lett 2007; 29:1045-50. [PMID: 17426925 DOI: 10.1007/s10529-007-9365-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Revised: 03/01/2007] [Accepted: 03/02/2007] [Indexed: 10/23/2022]
Abstract
The transformation of fluorobenzene (FB) by whole cell expressing toluene-4-monooxygenase (T4MO) resulted in the formation of various hydroxylated products. The predominant product was either 4-fluorophenol (4FP) or 4-fluorocatechol (4Fcat) depending on the ratio of biocatalyst to substrate concentration. The transformation of 1 mM FB by whole cells (1.5 mg CDW/ml) gave a 52% yield of 4Fcat as a single product. The yield of 4Fcat was improved 1.6-fold (80%) by adding 10 mM ascorbic acid to the biotransformations. A combination of two biocatalysts (whole cells expressing T4MO and cell free mushroom tyrosinase) also resulted in the transformation of FB (5 mM) to higher concentrations of 4Fcat (1.8 mM) compared to a whole cell biotransformation alone. However, mixed products were formed and the yield of 4Fcat from FB was lower using the two-step (tandem) method (27%) compared to the use of whole cells of P. mendocina KR1 alone (80%).
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Affiliation(s)
- Louise C Nolan
- School of Biomolecular and Biomedical Science, Centre for Synthesis and Chemical Biology, Conway Institute for Biomolecular and Biomedical Research, National University of Ireland, Belfield, Dublin, Republic of Ireland
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Biochemical characterisation of the coexisting tyrosinase and laccase in the soil bacterium Pseudomonas putida F6. Enzyme Microb Technol 2007. [DOI: 10.1016/j.enzmictec.2006.10.020] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Brooks SJ, Doyle EM, O’Connor KE. Tyrosol to hydroxytyrosol biotransformation by immobilised cell extracts of Pseudomonas putida F6. Enzyme Microb Technol 2006. [DOI: 10.1016/j.enzmictec.2005.10.025] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Vaidya BK, Suthar HK, Kasture S, Nene S. Purification of potato polyphenol oxidase (PPO) by partitioning in aqueous two-phase system. Biochem Eng J 2006. [DOI: 10.1016/j.bej.2005.10.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Nolan LC, O'Connor KE. A spectrophotometric method for the quantification of an enzyme activity producing 4-substituted phenols: determination of toluene-4-monooxygenase activity. Anal Biochem 2005; 344:224-31. [PMID: 16061193 DOI: 10.1016/j.ab.2005.05.032] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2005] [Revised: 05/17/2005] [Accepted: 05/21/2005] [Indexed: 11/20/2022]
Abstract
A spectrophotometric method for the quantitative determination of an enzyme activity resulting in the accumulation of 4-substituted phenols is described in this article. Toluene-4-monooxygenase (T4MO) activity in whole cells of Pseudomonas mendocina KR1 is used to demonstrate this method. This spectrophotometric assay is based on the coupling of T4MO activity with tyrosinase activity. The 4-substituted phenol, produced by the action of T4MO on the aromatic ring of a substituted arene, is a substrate for tyrosinase, which converts phenols to o-quinones. The latter react with the nucleophile 3-methyl-2-benzothiazolinone hydrazone (MBTH) to produce intensely colored products that absorb light maximally at different wavelengths, depending on the phenolic substrate used. The incubation of whole cells of P. mendocina KRI with fluorobenzene resulted in the accumulation of 4-fluorophenol. The coupling of T4MO activity with tyrosinase activity in the presence of fluorobenzene resulted in the formation of a colored product absorbing maximally at 480 nm. The molar absorptivity (epsilon) value for the o-quinone-MBTH adduct formed from 4-fluorophenol was determined experimentally to be 12,827 M(-1) cm(-1) with a linear range of quantification between 2.5 and 75 microM. The whole cell assay was run as a continuous indirect assay. The initial rates of T4MO activity toward fluorobenzene, as determined spectrophotometrically, were 61.8+/-4.4 nmol/min/mg P. mendocina KR1 protein (using mushroom tyrosinase), 64.9+/-4.6 nmol/min/mg P. mendocina KR1 protein (using cell extracts Pseudomonas putida F6), and, as determined by HPLC analysis, 62.6+/-1.4 nmol/min/mg P. mendocina KR1 protein.
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Affiliation(s)
- Louise C Nolan
- Department of Industrial Microbiology, Centre for Synthesis and Chemical Biology, Conway Institute for Biomolecular and Biomedical Research, National University of Ireland, University College Dublin, Belfield, Dublin 4, Republic of Ireland
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McMahon AM, Doyle EM, O’Connor KE. Detection and quantification of 4-substituted phenols: a comparison of mushroom tyrosinase and cell extracts of Pseudomonas putida F6. Enzyme Microb Technol 2005. [DOI: 10.1016/j.enzmictec.2005.01.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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