1
|
Pacetti A, Moretti S, Perrin C, Gelhaye E, Bieler E, Kassemeyer HH, Mugnai L, Farine S, Bertsch C. Grapevine Wood-Degrading Activity of Fomitiporia mediterranea M. Fisch.: A Focus on the Enzymatic Pathway Regulation. Front Microbiol 2022; 13:844264. [PMID: 35369524 PMCID: PMC8971955 DOI: 10.3389/fmicb.2022.844264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 02/04/2022] [Indexed: 11/13/2022] Open
Abstract
Fomitiporia mediterranea is a Basidiomycetes fungus associated with some of the Esca complex diseases and responsible for decay in grapevine wood. Its role in the onset of foliar symptoms has recently been reconsidered, mainly after evidence showing a reduction in foliar symptom expression after removal of rotten wood. The study of its degradation pathways has already been approached by other authors, and with this study much information is consolidated. A microscopic observation of degraded wood provides a first approach to the characterization of F. mediterranea modalities of wood cellular structure degradation. The decay of grapevine wood was reproduced in vitro, and the measurement of each wood-forming polymer loss highlighted characteristics of F. mediterranea common to selective white rot and showed how fungal strain and vine variety are factors determining the wood degradation. All these observations were supported by the analysis of the laccase and manganese peroxidase enzyme activity, as well as by the expression of the genes coding 6 putative laccase isoforms and 3 manganese peroxidase isoforms, thereby highlighting substantial intraspecific variability.
Collapse
Affiliation(s)
- Andrea Pacetti
- Laboratoire Vigne Biotechnologies et Environnement UR-3991, Université de Haute Alsace, Colmar, France
- Department of Agricultural, Food, Environmental and Forestry Science and Technology (DAGRI), Plant Pathology and Entomology Section, University of Florence, Florence, Italy
| | - Samuele Moretti
- Laboratoire Vigne Biotechnologies et Environnement UR-3991, Université de Haute Alsace, Colmar, France
| | - Célia Perrin
- Laboratoire Vigne Biotechnologies et Environnement UR-3991, Université de Haute Alsace, Colmar, France
| | - Eric Gelhaye
- Faculté des Sciences et Technologies Boulevard des Aiguillettes, UMR IAM - Université de Lorraine, Vandoeuvre-lès-Nancy, France
| | - Evi Bieler
- Swiss Nanoscience Institute (SNI) – Nano Imaging, University of Basel, Basel, Switzerland
| | - Hanns-Heinz Kassemeyer
- Swiss Nanoscience Institute (SNI) – Nano Imaging, University of Basel, Basel, Switzerland
- State Institute for Viticulture, Plant Pathology & Diagnostics, Freiburg, Germany
- Faculty of Biology, Plant Biomechanics Group and Botanic Garden, Albert-Ludwigs-Universität Freiburg, Freiburg im Breisgau, Germany
| | - Laura Mugnai
- Department of Agricultural, Food, Environmental and Forestry Science and Technology (DAGRI), Plant Pathology and Entomology Section, University of Florence, Florence, Italy
| | - Sibylle Farine
- Laboratoire Vigne Biotechnologies et Environnement UR-3991, Université de Haute Alsace, Colmar, France
| | - Christophe Bertsch
- Laboratoire Vigne Biotechnologies et Environnement UR-3991, Université de Haute Alsace, Colmar, France
| |
Collapse
|
2
|
Kainthola J, Podder A, Fechner M, Goel R. An overview of fungal pretreatment processes for anaerobic digestion: Applications, bottlenecks and future needs. BIORESOURCE TECHNOLOGY 2021; 321:124397. [PMID: 33249324 DOI: 10.1016/j.biortech.2020.124397] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 11/01/2020] [Accepted: 11/06/2020] [Indexed: 06/12/2023]
Abstract
Lignin modifying or extracellular enzymes secreted by the white rot fungi have the ability of degrading wide range of lignocellulosic substrates and organic pollutants. Lignocellulosic biomass, despite being a renewable source of energy, is difficult to hydrolyse (hydrolysis being rate-limiting stage in anaerobic digestion process). Various pre-treatment techniques like physical, chemical, thermo-chemical and biological to enhance the accessibility of microbes to carbohydrates have been studied. Recently, usage of white- rot fungi in a biological pre-treatment technique have received renewed interest due to its low cost and eco-friendly nature. This review deals with: a) lignocellulosic biomass recalcitrance, b) various pre-treatment techniques and its economic feasibility, c) delignification and hydrolysis mechanism using white-rot fungi, d) factors controlling white-rot fungi pre- treatment process, and e) improvement in methane production through solid-state anaerobic digestion of white-rot fungi pre-treated lignocellulosic biomass. Finally a future perspective is also included.
Collapse
Affiliation(s)
- Jyoti Kainthola
- Department of Civil Engineering, National Institute of Technology Raipur, Raipur 492010, Chhattisgarh, India
| | - Aditi Podder
- Civil & Environmental Engineering, University of Utah, Salt Lake City, UT 84112, United States
| | - Marcus Fechner
- Civil & Environmental Engineering, University of Utah, Salt Lake City, UT 84112, United States
| | - Ramesh Goel
- Civil & Environmental Engineering, University of Utah, Salt Lake City, UT 84112, United States.
| |
Collapse
|
3
|
Watanabe T, Yoshioka K, Kido A, Lee J, Akiyoshi H, Watanabe T. Preparation of intracellular proteins from a white-rot fungus surrounded by polysaccharide sheath and optimization of their two-dimensional electrophoresis for proteomic studies. J Microbiol Methods 2017; 142:63-70. [PMID: 28916445 DOI: 10.1016/j.mimet.2017.09.009] [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: 07/21/2017] [Revised: 09/11/2017] [Accepted: 09/11/2017] [Indexed: 11/26/2022]
Abstract
The functions and properties of fungal sheath, an extracellular polysaccharide produced by many white-rot fungi, have been studied. However, the strong adherence of the sheath to fungal hyphae had been a major impediment in preparing intracellular proteins from the fungi and analyzing their cellular responses. To overcome this issue, we developed a rapid and easy method to remove the polysaccharide sheath using a selective lignin degrader, Ceriporiopsis subvermispora, which produces large sheath amounts in the presence of a lignin-derived aromatic compound. Using this approach, we achieved thorough removal of sheath and cell disruption using beads and a solution with a high protein-solubilizing power, which enabled the efficient extraction of intracellular proteins from C. subvermispora surrounded by sheath. In addition, for proteomic analysis, we investigated whether these extracted proteins were compatible with two-dimensional electrophoresis. By efficiently concentrating on protein solubilization in the first dimension and using a stacking gel in the second dimension, we successfully obtained a high-resolution proteome map of C. subvermispora. We also used the same proteins for fluorescence two-dimensional difference gel electrophoresis to obtain the quantitative protein expression profiles. These steps demonstrated that two-dimensional electrophoresis-based proteomics can be used to clarify the composition of intracellular proteins from sheath-producing white-rot fungi.
Collapse
Affiliation(s)
- Takahito Watanabe
- Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Japan.
| | - Koichi Yoshioka
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan; Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Japan
| | - Ayako Kido
- Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Japan
| | - Junseok Lee
- Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Japan
| | - Hikari Akiyoshi
- Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Japan
| | - Takashi Watanabe
- Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Japan
| |
Collapse
|
4
|
Šlosarčíková P, Novotný Č, Malachová K, Válková H, Fojtík J. Effect of yeasts on biodegradation potential of immobilized cultures of white rot fungi. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 589:146-152. [PMID: 28259434 DOI: 10.1016/j.scitotenv.2017.02.079] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Revised: 12/30/2016] [Accepted: 02/09/2017] [Indexed: 06/06/2023]
Abstract
The aim was to investigate the effect of yeast organisms on the degradation process by immobilized cultures of ligninolytic fungi. Immobilization was accomplished by 7-day colonization of polyamide mesh with mycelial fragments. Irpex lacteus decolorized >90% of the initial concentration of 150mgl-1 of anthraquinone Remazol Brilliant Blue R dye in three subsequent decolorization cycles and the degradation capacity was not negatively affected by the presence of 106Saccharomyces cerevisiae cells per ml in the mixed culture. The yeast was not able to degrade the dye. I. lacteus biofilm was also resistant to bacterial infection with E. coli. Inoculation of the yeast to pre-formed I. lacteus biofilm culture resulted in a reduction of fungal biomass by 27%. Levels of LiP, MnP and laccase of I. lacteus were not much influenced by S. cerevisiae or E. coli. Similar resilience of P. ostreatus biofilms was observed after exposure to yeast Issatchenkia occidentalis when the fungal degradation capacity measured with Reactive Orange 16 azo dye was maintained over two decolorization cycles. I. occidentalis did not degrade the dye under the conditions used. Formation of densely packed fungal biofilms with abundant extracellular polysaccharide was not impeded by the yeast. Increase of MnP and laccase levels attributable to the presence of I. occidentalis was observed.
Collapse
Affiliation(s)
- Pavlína Šlosarčíková
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czech Republic.
| | - Čeněk Novotný
- Institute of Microbiology, Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic.
| | - Kateřina Malachová
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czech Republic.
| | - Hana Válková
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czech Republic.
| | - Jindřich Fojtík
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czech Republic.
| |
Collapse
|
5
|
Stajić M, Vukojević J, Milovanović I, Ćilerdžić J, Knežević A. Role of Mushroom Mn-Oxidizing Peroxidases in Biomass Conversion. ACTA ACUST UNITED AC 2016. [DOI: 10.1007/978-3-319-43679-1_10] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
|
6
|
Busse N, Fuchs F, Kraume M, Czermak P. Treatment of enzyme-initiated delignification reaction mixtures with ceramic ultrafiltration membranes: Experimental investigations and modeling approach. SEP SCI TECHNOL 2016. [DOI: 10.1080/01496395.2016.1167739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
7
|
Bánfi R, Pohner Z, Kovács J, Luzics S, Nagy A, Dudás M, Tanos P, Márialigeti K, Vajna B. Characterisation of the large-scale production process of oyster mushroom ( Pleurotus ostreatus ) with the analysis of succession and spatial heterogeneity of lignocellulolytic enzyme activities. Fungal Biol 2015; 119:1354-1363. [DOI: 10.1016/j.funbio.2015.10.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 09/05/2015] [Accepted: 10/02/2015] [Indexed: 01/24/2023]
|
8
|
Daniel G. Fungal and Bacterial Biodegradation: White Rots, Brown Rots, Soft Rots, and Bacteria. ACS SYMPOSIUM SERIES 2014. [DOI: 10.1021/bk-2014-1158.ch002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Geoffrey Daniel
- Department of Forest Products/Wood Science, Swedish University of Agricultural Sciences, Box 7008, Uppsala, Sweden
| |
Collapse
|
9
|
Bubner P, Plank H, Nidetzky B. Visualizing cellulase activity. Biotechnol Bioeng 2013; 110:1529-49. [DOI: 10.1002/bit.24884] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 01/08/2013] [Accepted: 02/22/2013] [Indexed: 11/08/2022]
|
10
|
Contreras E, Urra J, Vásquez C, Palma C. Detoxification of azo dyes mediated by cell-free supernatant culture with manganese-dependent peroxidase activity: Effect of Mn2+ concentration and H2O2 dose. Biotechnol Prog 2011; 28:114-20. [DOI: 10.1002/btpr.722] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 08/19/2011] [Indexed: 11/10/2022]
|
11
|
Kapich AN, Galkin S, Hatakka A. Effect of phenolic acids on manganese peroxidase-dependent peroxidation of linoleic acid and degradation of a non-phenolic lignin model compound. BIOCATAL BIOTRANSFOR 2009. [DOI: 10.1080/10242420701379957] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
12
|
Stajic´ M, Vukojevic´ J, Duletic´-Lauševic´ S. Biology ofPleurotus eryngiiand role in biotechnological processes: a review. Crit Rev Biotechnol 2009; 29:55-66. [DOI: 10.1080/07388550802688821] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
13
|
Báidez AG, Gómez P, Del Río JA, Ortuño A. Dysfunctionality of the xylem in Olea europaea L. Plants associated with the infection process by Verticillium dahliae Kleb. Role of phenolic compounds in plant defense mechanism. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2007; 55:3373-7. [PMID: 17394331 DOI: 10.1021/jf063166d] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Xylem ultrastructural modification and the possible participation of phenolic compounds in the natural defense or resistance mechanisms of olive plants infected with Verticillium dahliae Kleb. were studied. Microscopic study showed that the mycelium propagated and passed from one element to another through the pit. The formation of tyloses and aggregates contributed to obstruction of the xylem lumen. In vivo changes in the levels of these phenolic compounds in infected olive plants and their antifungal activity against Verticillium dahliae Kleb., as revealed by in vitro study, strongly suggest that they are involved in natural defense or resistance mechanisms in this plant material, the most active being quercetin and luteolin aglycons, followed by rutin, oleuropein, luteolin-7-glucoside, tyrosol, p-coumaric acid, and catechin. .
Collapse
Affiliation(s)
- Ana G Báidez
- Plant Biology Department, Faculty of Biology, University of Murcia, 30100 Espinardo, Murcia, Spain
| | | | | | | |
Collapse
|
14
|
Daniel G, Volc J, Niku-Paavola ML. Cryo-FE-SEM & TEM immuno-techniques reveal new details for understanding white-rot decay of lignocellulose. C R Biol 2005; 327:861-71. [PMID: 15587077 DOI: 10.1016/j.crvi.2004.08.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
High-resolution Cryo-Field Emission Scanning Electron Microscopy (HR-Cryo-FE-SEM) and immuno-cytochemistry were used to reveal novel details on the morphological events and spatial distribution of oxidoreductive enzymes during the degradation of birch wood by the white-rot fungi Phlebia radiata and mutant strain P radiata Cel 26. Cryo-observations of fractured fibres showed degradation across the cell wall by P. radiata (wild) to progress by delamination and removal of concentric orientated aggregates from the secondary S2 cell wall. Decay by P radiata Cel 26 progressed by removal of materials (lignin and hemicelluloses) between the aggregates (primarily cellulose) that remained even after advanced decay. With both decay patterns, extracellular slime materials were present uniting lumina hyphae with the attacked fibre wall. The extracellular slime material had two morphological forms: viz a fibrillar (often tripartite) and a 'gel-form', the former found in discrete bands progressing across the lumen onto the fibre wall. Using TEM immunocytochemistry, laccase, manganese peroxidase (MnP) and diarylpropane enzymes were localized in the periplasmic space of luminal hyphae, in association with the cell membrane, periplasmic vesicles and fungal cell wall. Extracellularly, the three enzymes were found associated with the slime and tripartite membranes and with the birch cell walls at all stages of attack through to middle lamella corner decay. Enzyme distribution was correlated with morphological changes in cell wall structure. The association of extracellular slime with these enzymes and sites of decay strongly suggests a major role for this matrix in fibre cell wall decomposition.
Collapse
Affiliation(s)
- Geoffrey Daniel
- Wood Ultrastructure Research Centre, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden.
| | | | | |
Collapse
|
15
|
Milagres AM, Sales RM. Evaluating the basidiomycetes Poria medula-panis and Wolfiporia cocos for xylanase production. Enzyme Microb Technol 2001; 28:522-526. [PMID: 11267647 DOI: 10.1016/s0141-0229(00)00364-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Xylanase, oxidative enzymes and iron-binding compounds were detected in the filtrates of Wolfiporia cocos and Poria medula-panis grown in wheat bran liquid medium. Xylanase and iron-binding compounds were produced at high levels by the brown-rot fungus (BR) W. cocos and at low levels by the white-rot fungus (WR) P. medula-panis. Phenoloxidase was produced only by P. medula-panis. Polyacrylamide gel electrophoresis (PAGE) (SDS-PAGE) showed a wide variety of bands for extracellular proteins produced by W.cocos, with low molecular weight (<30 kDa) and minor bands with molecular weight above 45 kDa. Two bands with xylanase activity derived from W. cocos extracts were detected in the gels, whereas many different bands with xylanase activity were found in the extracts from P. medula-panis. P. medula-panis is a selective lignin degrader, whereas W. cocos preferentially removes cellulose from wood.
Collapse
Affiliation(s)
- A M.F. Milagres
- Department of Biotechnology, Faculdade de Engenharia Química de Lorena, CP 116, 12600-000, Lorena, SP, Brazil
| | | |
Collapse
|
16
|
Enoki M, Watanabe T, Nakagame S, Koller K, Messner K, Honda Y, Kuwahara M. Extracellular lipid peroxidation of selective white-rot fungus, Ceriporiopsis subvermispora. FEMS Microbiol Lett 1999; 180:205-11. [PMID: 10556713 DOI: 10.1111/j.1574-6968.1999.tb08797.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Ceriporiopsis subvermispora is capable of decomposing lignin without penetration of enzymes into wood cell walls. To elucidate the mechanism of lignolysis at a site far from enzymes, peroxidation of low molecular mass compounds produced by this fungus was analyzed. C. subvermispora produced free 9,12-octadecadienoic, 9-octadecenoic, 11-octadecenoic, hexadecanoic and octadecanoic acids, predominantly at an early stage of cultivation on wood meal cultures. In prolonged cultivation period after 2 weeks, the amount of intact fatty acids decreased with increasing organic hydroperoxide and TBARS production. These results suggest that lignin degradation by C. subvermispora is related to extracellular lipid peroxidation.
Collapse
Affiliation(s)
- M Enoki
- Laboratory of Biomass Conversion, Wood Research Institute, Kyoto University, Gokasho, Uji, Kyoto, Japan
| | | | | | | | | | | | | |
Collapse
|
17
|
Watanabe T, Koller K, Messner K. Copper-dependent depolymerization of lignin in the presence of fungal metabolite, pyridine. J Biotechnol 1998; 62:221-30. [PMID: 9729805 DOI: 10.1016/s0168-1656(98)00063-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Thus far, it has not been recognized that copper complexes are able to depolymerize lignin under physiological conditions of white rot decay. However, we have found that both phenolic and non-phenolic synthetic lignins were intensively depolymerized by Cu(II) and lipid hydroperoxide model compounds in the presence of a metabolite of ligninolytic fungi, pyridine at room temperature in aqueous media. Treatment of 14C-labeled oxygen-prebleached kraft pulp (OKP) by the copper-dependent reaction evidenced effectiveness of this reaction for the delignification of kraft pulps. In contrast to the organic peroxide system, Cu(II)/pyr/H2O2 system was much less effective for the lignin depolymerization. However, treatment of unbleached kraft pulp (UKP) by Cu(II)/H2O2 and Cu(II)/pyr/H2O2 systems demonstrated that the damage of cellulose was suppressed by the coordination of pyridine although high brightness gain was obtained independently of the presence of the coordinator. Spin trapping experiments demonstrated that not hydroxyl radical but superoxide anion is involved in the Cu(II)/pyr/H2O2 system. This finding not only introduces a new concept of non-enzymatic lignin biodegradation by wood-degrading fungi but also presents a new strategy for decomposing lignin and lignin-related compounds by copper complexes and peroxide-producing system.
Collapse
Affiliation(s)
- T Watanabe
- Laboratory of Biomass Conversion, Wood Research Institute, Kyoto University, Japan.
| | | | | |
Collapse
|
18
|
Differential phenol-induced laccase activity and total oxidative capacity of the S and P intersterility groups of the conifer root pathogen Heterobasidion annosum. Microbiol Res 1998. [DOI: 10.1016/s0944-5013(98)80024-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
19
|
Barnett P, Kruitbosch DL, Hemrika W, Dekker HL, Wever R. The regulation of the vanadium chloroperoxidase from Curvularia inaequalis. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1352:73-84. [PMID: 9177485 DOI: 10.1016/s0167-4781(96)00238-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The effects of carbon and nitrogen source on the regulation of the vanadium chloroperoxidase secreted by the fungus Curnularia inaequalis were investigated. The addition of glucose showed a repressing effect on both the observed messenger RNA level and the measured enzyme activities, whereas the addition of glutamate as nitrogen source and the addition of both glutamate and glycerol had no effect. Addition of vanadate had no effect on the level of mRNA. Eight hundred base pairs of the upstream promoter region of vCPO were sequenced and various features of interest are highlighted. Closer inspection of the mycelium revealed that once secreted, vCPO probably remains tightly associated with the hyphae in two forms, one of which may be a proform of the enzyme. A possible cleavage event at the C-terminus may lower its potential for hyphal association and permit its disassociation into the growth medium. A putative role for the vanadium chloroperoxidase is put forward.
Collapse
Affiliation(s)
- P Barnett
- Department of Biochemistry, E.C. Slater Institute, University of Amsterdam, The Netherlands
| | | | | | | | | |
Collapse
|
20
|
Call H, Mücke I. History, overview and applications of mediated lignolytic systems, especially laccase-mediator-systems (Lignozym®-process). J Biotechnol 1997. [DOI: 10.1016/s0168-1656(97)01683-0] [Citation(s) in RCA: 360] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
21
|
Guillén F, Martínez MJ, Muñoz C, Martínez AT. Quinone redox cycling in the ligninolytic fungus Pleurotus eryngii leading to extracellular production of superoxide anion radical. Arch Biochem Biophys 1997; 339:190-9. [PMID: 9056249 DOI: 10.1006/abbi.1996.9834] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Quinone redox cycling is generally known as an intracellular process that implies the reduction of quinones (Q) into semiquinones (Q-.) or hydroquinones (QH2), which autoxidize reducing oxygen to superoxide anion radical (O-.2). We demonstrate here for the first time the existence of quinone redox cycling in a ligninolytic fungus, Pleurotus eryngii, showing two particularities: extracellular production of O-.2 and involvement of ligninolytic enzymes. Experiments were performed with P. eryngii cultures, showing laccase activity, and four quinones: 1,4-benzoquinone (BQ), 2-methyl-1,4-benzoquinone (MeBQ), 2,3,5,6-tetramethyl-1,4-benzoquinone (duroquinone, DQ), and 2-methyl-1,4-naphthoquinone (menadione, MD). The overall process consisted of cell-bound divalent reduction of quinones, followed by extracellular laccase-mediated oxidation of hydroquinones into semiquinones, which autoxidized to a certain extent producing O-.2 (at the pH values of natural degradation of lignin, some autoxidation of hydroquinones was observed only with DQH2 and MDH2). The existence of a redox cyclic system involving quinones was evidenced by determining the chemical state of quinones along incubation under several conditions (either different O2 concentrations and pH values or laccase amounts). Thus, QH2/Q ratios at system equilibrium decreased as either pH values and oxygen concentration (allowing hydroquinones autoxidation) or the amount of laccase increased. Once the cyclic nature of the system was demonstrated, special attention was paid to the production of O-.2 during hydroquinone oxidation. Except in the case of BQH2, production of O-.2 was found in samples containing hydroquinones and laccase. By the use of agents promoting the autoxidation of semiquinones (superoxide dismutase and Mn2+), production of O-.2 during oxidation of BQH2 could finally be demonstrated.
Collapse
Affiliation(s)
- F Guillén
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Velázquez, Madrid, Spain
| | | | | | | |
Collapse
|
22
|
Dutton MV, Evans CS. Oxalate production by fungi: its role in pathogenicity and ecology in the soil environment. Can J Microbiol 1996. [DOI: 10.1139/m96-114] [Citation(s) in RCA: 446] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Oxalate secretion by fungi provides many advantages for their growth and colonization of substrates. The role of oxalic acid in pathogenesis is through acidification of host tissues and sequestration of calcium from host cell walls. The formation of calcium oxalate crystals weakens the cell walls, thereby allowing polygalacturonase to effect degradation more rapidly in a synergistic response. There is good correlation between pathogenesis, virulence, and oxalic acid secretion. Solubility of soil nutrients is achieved by soil-living species, when cations freed by oxalate diffusing in clay layers increases the effective solubility of Al and Fe. Oxalate retained in hyphal mats of mycorrhizal species increases phosphate and sulphate availability. The formation of calcium oxalate crystals provides a reservoir of calcium in the ecosystem. The ability of oxalate to bind divalent cations permits detoxification of copper, particularly evident in wood preserved with copper salts. Oxalate plays a unique role in lignocellulose degradation by wood-rotting basidiomycetes, acting as a low molecular mass agent initiating decay. In addition, in white-rot fungi oxalate acts as a potential electron donor for lignin-peroxidase catalysed reduction and chelates manganese, allowing the dissolution of Mn3+from the manganese–enzyme complex and thus stimulating extracellular manganese peroxidase activity. The biosynthesis and degradation of oxalate are discussed.Key words: oxalic acid, calcium oxalate, pathogenicity, fungi.
Collapse
|
23
|
Caporale C, Garzillo AM, Caruso C, Buonocore V. Characterization of extracellular proteases from Trametes trogii. PHYTOCHEMISTRY 1996; 41:385-393. [PMID: 8821431 DOI: 10.1016/0031-9422(96)83284-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The peptidase activities excreted in culture broths of Trametes trogii mycelium have been identified by determining the digestion pathway of various peptides. Insulin beta-chain (30 residues), procasomorphin (10 residues) and two peptides of five residues (proctolin and thymosin alpha 1 fragment 23-27) were utilized as model substrates. Aminopeptidase, carboxypeptidase, endopeptidase and dipeptidyl aminopeptidase activities were revealed and information on their specificity was deduced. Preliminary data on the pH-dependent activity of the peptidases were also obtained by sequence analysis of the fragment mixtures produced at different pH values.
Collapse
Affiliation(s)
- C Caporale
- Dipartimento di Agrobiologia od Agrochimica, Universita' della Tuscia, Viterbo, Italy
| | | | | | | |
Collapse
|
24
|
Rashid MH, Siddiqui KS. The stability of extracellular beta-glucosidase from Aspergillus niger is significantly enhanced by non-covalently attached polysaccharides. Folia Microbiol (Praha) 1996; 41:341-6. [PMID: 9131791 DOI: 10.1007/bf02814712] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The removal of noncovalently bound polysaccharide coating from the extracellular enzymes of Aspergillus niger, by the technique of compartmental electrophoresis, had a very dramatic effect on the stability of beta-glucosidase. The polysaccharide-beta-glucosidase complex was extremely resistant to proteinases and far more stable against urea and temperature as compared with polysaccharide-free beta-glucosidase. The beta-glucosidase-polysaccharide complex was 18-, 36-, 40- and 82-fold more stable against chymotrypsin, 3 mol/L urea, total thermal denaturation and irreversible thermal denaturation, respectively, as compared with polysaccharide-free beta-glucosidase. The activation energy of polysaccharide-complexed beta-glucosidase (55 kJ/mol) was lower than polysaccharide-free enzyme (61 kJ/mol), indicating a slight activation of the enzyme by the polysaccharide. No significant difference could be detected in the specificity constant (V/K(m)) for A-nitrophenyl beta-D-glucopyranoside between polysaccharide-free and polysaccharide-complexed beta-glucosidase. We suggest that the function of these polysaccharides secreted by fungi including A. niger might be to protect the extracellular enzymes from proteolytic degradation, hence increasing their life span.
Collapse
Affiliation(s)
- M H Rashid
- National Institute for Biotechnology & Genetic Engineering, Faisalabad, Pakistan
| | | |
Collapse
|
25
|
Broda P, Birch PR, Brooks PR, Sims PF. PCR-mediated analysis of lignocellulolytic gene transcription by Phanerochaete chrysosporium: substrate-dependent differential expression within gene families. Appl Environ Microbiol 1995; 61:2358-64. [PMID: 7793956 PMCID: PMC167507 DOI: 10.1128/aem.61.6.2358-2364.1995] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We compare the kinetics of appearance of supernatant enzyme activities (lignin peroxidase, manganese peroxidase, and cellulase) and gene expression (LIG, mnp, and cbhI gene families and the unique cbhII gene) in Phanerochaete chrysosporium ME446 when grown on four different carbon sources: ball-milled straw, representing the natural substrate lignocellulose; Avicel as a crystalline cellulose; and high and low concentrations of glucose, in all cases with limiting nitrogen. PCR-based technology utilizing pairs of primers specific for particular genes showed that there is differential expression between and within the families. There were a number of instances of mRNA species being present only on a single day, implying tight regulation of lignocellulose degradation at the mRNA level. The patterns of extracellular enzyme activities and mnp and cbh gene expression are similar whereas LIG gene expression can be detected when no corresponding enzyme activity is observed in the extracellular supernatant. The enzyme produced under these conditions is presumably sequestered by the mycelium and is likely to be functionally significant. Another striking result is that cellulose, in the form of Avicel, elicits the expression of three LIG gene for which there is no expression under the same conditions with the other carbon sources.
Collapse
Affiliation(s)
- P Broda
- Department of Biochemistry and Applied Molecular Biology, University of Manchester Institute of Science and Technology, United Kingdom
| | | | | | | |
Collapse
|
26
|
Simons BH, Barnett P, Vollenbroek EG, Dekker HL, Muijsers AO, Messerschmidt A, Wever R. Primary structure and characterization of the vanadium chloroperoxidase from the fungus Curvularia inaequalis. EUROPEAN JOURNAL OF BIOCHEMISTRY 1995; 229:566-74. [PMID: 7744081 DOI: 10.1111/j.1432-1033.1995.tb20499.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Using reverse transcription of messenger RNA followed by amplification using the polymerase chain reaction, three overlapping cDNA fragments encompassing the encoding sequence of the vanadium chloroperoxidase from the fungus Curvularia inaequalis were isolated and sequenced. The sequence was confirmed by DNA sequence analysis of genomic DNA. The deduced amino acid sequence predicts a protein of 609 residues with a mass of 67488 Da. Competitive reverse-transcription polymerase chain reaction analysis indicates that vanadium chloroperoxidase expression takes place in the secondary-growth phase initiated by nutrient depletion. Southern-blot analysis of genomic DNA indicates that there is only a single gene encoding the vanadium chloroperoxidase and that no isoenzymes are present. The N-terminal amino acid residue was blocked and could not be determined by amino acid sequencing, although evidence is presented showing that the N-terminal region starts very close to the first encoded methionine residue. Although the vanadium chloroperoxidase is secreted, it was not possible to assign a leader peptide. The protein contains two putative N-glycosylation sites but experiments indicate that the protein is non-glycosylated. Two cysteine residues are present in the protein both as free thiols: no disulphide bridging was found. Metal analysis revealed that iron, copper, and calcium do not constitute part of the protein. Zinc was found at a ratio of 0.3 +/- 0.04 mol/mol protein. Boiling and subsequent SDS/PAGE of the protein sample showed a typical degradation pattern of the enzyme. Amino acid sequence analysis of the resulting peptides showed that the cleavage took place at Asp-Pro bonds of which six are located throughout the protein. No sequence similarity with other known peroxidases was found except for one small region, sharing limited similarity with bacterial haloperoxidases and other alpha/beta-hydrolase-fold enzymes. In the case of the bacterial bromoperoxidases from this group, a methionine located in this region was suggested to have a role in catalysis. Methionine, however, was not involved in the catalysis of the vanadium chloroperoxidase.
Collapse
Affiliation(s)
- B H Simons
- E. C. Slater Institute, Department of Biochemistry, Amsterdam, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
27
|
Peláez F, Martínez M, Martínez A. Screening of 68 species of basidiomycetes for enzymes involved in lignin degradation. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/s0953-7562(09)80313-4] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
28
|
Siddiqui KS, Rashid MH, Shemsi AM, Rajoka MI. A simple and nondestructive method for the separation of polysaccharides from beta-glucosidase produced extracellularly by Aspergillus niger. Enzyme Microb Technol 1994; 16:912-7. [PMID: 7765232 DOI: 10.1016/0141-0229(94)90067-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
An apparatus based on electrophoresis has been devised that removes noncovalently bound polysaccharides from extracellular proteins of Aspergillus niger with concomitant partial beta-glucosidase purification and concentration. The apparatus consists of a series of three chambers separated by polyacrylamide gels. Dialyzed and concentrated crude extract of Aspergillus niger containing beta-glucosidase was poured into the middle chamber, while smaller anodic and cathodic chambers contained buffer. When electric current was applied, negatively charged protein-polysaccharide complexes moved toward the anode. Most of the negatively charged proteins, including beta-glucosidase, crossed the gel barrier into the anodic compartment, while neutral polysaccharides were either trapped in the gels or remained in the middle chamber. In this way, 125 ml of dialyzed and concentrated crude extract of Aspergillus niger was processed. Therefore, after 24 h of electrophoresis, 68% of the proteins and 90% of the beta-glucosidase activity, but only negligible amounts of polysaccharide, were transferred to the anodic chamber. The removal of high-molecular-weight polysaccharide from beta-glucosidase had a detrimental effect on the stability of the enzyme.
Collapse
Affiliation(s)
- K S Siddiqui
- National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan
| | | | | | | |
Collapse
|
29
|
Jönsson L, Becker HG, Nyman PO. A novel type of peroxidase gene from the white-rot fungus Trametes versicolor. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1207:255-9. [PMID: 8075158 DOI: 10.1016/0167-4838(94)00083-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The wood-decaying fungus Trametes versicolor secretes a large number of peroxidase isozymes, presumed to partake in the degradation of lignin. From enzymic studies, two types of peroxidases have been distinguished: lignin peroxidases and manganese peroxidases. We here report the finding of a T. versicolor peroxidase gene, PG V, which displays several features not observed in previously studied peroxidase genes from white-rot fungi, such as a high number of introns (12). Eight of the 12 introns have positions equivalent to introns of peroxidase genes from another white-rot fungus, Phanerochaete chrysosporium. The gene structure of PG V appears to be primarily related to known lignin peroxidase genes, while the encoded mature 339-residue protein has several characteristics in common with manganese peroxidases. Analyses further indicate that PG V encodes a Ser instead of an Asn at a position regarded as invariant within the enzyme superfamily, with the side chain involved in hydrogen bonding with the distal His.
Collapse
Affiliation(s)
- L Jönsson
- Chemical Center, University of Lund, Sweden
| | | | | |
Collapse
|
30
|
Burns P, Yeo P, Keshavarz T, Roller S, Evans C. Physiological studies of exopolysaccharide production from the basidiomycete Pleurotus sp. florida. Enzyme Microb Technol 1994. [DOI: 10.1016/0141-0229(94)90120-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
31
|
Guill�n F, Mart�nez AT, Mart�nez MJ, Evans CS. Hydrogen-peroxide-producing system of Pleurotus eryngii involving the extracellular enzyme aryl-alcohol oxidase. Appl Microbiol Biotechnol 1994. [DOI: 10.1007/bf00212259] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
32
|
Guillén F, Martínez AT, Martínez MJ, Evans CS. Hydrogen-peroxide-producing system ofPleurotus eryngii involving the extracellular enzyme aryl-alcohol oxidase. Appl Microbiol Biotechnol 1994. [DOI: 10.1007/bf00939037] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
33
|
|
34
|
MartÃnez AT, Camarero S, Guillén F, Gutiérrez A, Muñoz C, Varela E, MartÃnez MJ, Barrasa J, Ruel K, Pelayo J. Progress in biopulping of non-woody materials: Chemical, enzymatic and ultrastructural aspects of wheat straw delignification with ligninolytic fungi from the genusPleurotus. FEMS Microbiol Rev 1994. [DOI: 10.1111/j.1574-6976.1994.tb00047.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
|
35
|
Evans C, Dutton M, Guillén F, Veness R. Enzymes and small molecular mass agents involved with lignocellulose degradation. FEMS Microbiol Rev 1994. [DOI: 10.1111/j.1574-6976.1994.tb00044.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
36
|
Schoemaker HE, Lundell TK, Hatakka AI, Piontek K. The oxidation of veratryl alcohol, dimeric lignin models and lignin by lignin peroxidase: The redox cycle revisited. FEMS Microbiol Rev 1994. [DOI: 10.1111/j.1574-6976.1994.tb00052.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
37
|
Messner K, Srebotnik E. Biopulping: An overview of developments in an environmentally safe paper-making technology. FEMS Microbiol Rev 1994. [DOI: 10.1111/j.1574-6976.1994.tb00054.x] [Citation(s) in RCA: 126] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
38
|
|
39
|
Nicole M, Chamberland H, Rioux D, Lecours N, Rio B, Geiger JP, Ouellette GB. A Cytochemical Study of Extracellular Sheaths Associated with
Rigidoporus lignosus
during Wood Decay. Appl Environ Microbiol 1993; 59:2578-88. [PMID: 16349017 PMCID: PMC182323 DOI: 10.1128/aem.59.8.2578-2588.1993] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An ultrastructural and cytochemical investigation of the development of
Rigidoporus lignosus
, a white-rot fungus inoculated into wood blocks, was carried out to gain better insight into the structure and role of the extracellular sheaths produced by this fungus during wood degradation. Fungal sheaths had a dense or loose fibrillar appearance and were differentiated from the fungal cell wall early after wood inoculation. Close association between extracellular fibrils and wood cell walls was observed at both early and advanced stages of wood alteration. Fungal sheaths were often seen deep in host cell walls, sometimes enclosing residual wood fragments. Specific gold probes were used to investigate the chemical nature of
R. lignosus
sheaths. While labeling of chitin, pectin, β-1,4- and β-1,3-glucans, β-glucosides, galactosamine, mannose, sialic acid, RNA, fucose, and fimbrial proteins over fungal sheaths did not succeed, galactose residues and laccase (a fungal phenoloxidase) were found to be present. The positive reaction of sheaths with the PATAg test indicates that polysaccharides such as β-1,6-glucans are important components. Our data suggest that extracellular sheaths produced by
R. lignosus
during host cell colonization play an important role in wood degradation. Transportation of lignin-degrading enzymes by extracellular fibrils indicates that alteration of plant polymers may occur within fungal sheaths. It is also proposed that
R. lignosus
sheaths may be involved in recognition mechanisms in fungal cell-wood surface interactions.
Collapse
Affiliation(s)
- M Nicole
- Laboratoire de Phytopathologie, Institut Français de Recherche Scientifique pour le Développement en Coopération, B.P. 5045, 34000 Montpellier, France, and Forestry Canada, Quebec Region, Sainte-Foy, Quebec GIV 4C7, Canada
| | | | | | | | | | | | | |
Collapse
|
40
|
Oxalate production by Basidiomycetes, including the white-rot species Coriolus versicolor and Phanerochaete chrysosporium. Appl Microbiol Biotechnol 1993. [DOI: 10.1007/bf00166839] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
41
|
Tuor U, Wariishi H, Schoemaker HE, Gold MH. Oxidation of phenolic arylglycerol beta-aryl ether lignin model compounds by manganese peroxidase from Phanerochaete chrysosporium: oxidative cleavage of an alpha-carbonyl model compound. Biochemistry 1992; 31:4986-95. [PMID: 1599925 DOI: 10.1021/bi00136a011] [Citation(s) in RCA: 109] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Manganese peroxidase (MnP) oxidized 1-(3,5-dimethoxy-4-hydroxyphenyl)-2-(4-(hydroxymethyl)-2-methoxyphenoxy) -1,3-dihydroxypropane (I) in the presence of MnII and H2O2 to yield 1-(3,5-dimethoxy-4-hydroxyphenyl)- 2-(4-(hydroxymethyl)-2-methoxyphenoxy)-1-oxo-3-hydroxypropane (II), 2,6-dimethoxy-1,4-benzoquinone (III), 2,6-dimethoxy-1,4-dihydroxybenzene (IV), 2-(4-(hydroxymethyl)-2-methoxyphenoxy)-3-hydroxypropanal (V), syringaldehyde (VI), vanillyl alcohol (VII), and vanillin (VIII). MnP oxidized II to yield 2,6-dimethoxy-1,4-benzoquinone (III), 2,6-dimethoxy-1,4-dihydroxybenzene (IV), vanillyl alcohol (VII), vanillin (VIII), syringic acid (IX), and 2-(4-(hydroxymethyl)-2-methoxyphenoxy)-3-hydroxypropanoic acid (X). A chemically prepared MnIII-malonate complex catalyzed the same reactions. Oxidation of I and II in H2(18)O under argon resulted in incorporation of one atom of 18O into the quinone III and into the hydroquinone IV. Incorporation of one atom of oxygen from H2(18)O into syringic acid (IX) and the phenoxypropanoic acid X was also observed in the oxidation of II. These results are explained by mechanisms involving the initial one-electron oxidation of I or II by enzyme-generated MnIII to produce a phenoxy radical. This intermediate is further oxidized by MnIII to a cyclohexadienyl cation. Loss of a proton, followed by rearrangement of the quinone methide intermediate, yields the C alpha-oxo dimer II as the major product from substrate I. Alternatively, cyclohexadienyl cations are attacked by water. Subsequent alkyl-phenyl cleavage yields the hydroquinone IV and the phenoxypropanal V from I, and IV and the phenoxypropanoic acid X from II, respectively. The initial phenoxy radical also can undergo C alpha-C beta bond cleavage, yielding syringaldehyde (VI) and a C6-C2-ether radical from I and syringic acid (IX) and the same C6-C2-ether radical from II. The C6-C2-ether radical is scavenged by O2 or further oxidized by MnIII, subsequently leading to release of vanillyl alcohol (VII). VII and IV are oxidized to vanillin (VIII) and the quinone III, respectively.
Collapse
Affiliation(s)
- U Tuor
- Department of Chemical and Biological Sciences, Oregon Graduate Institute of Science and Technology, Beaverton 97006-1999
| | | | | | | |
Collapse
|