Basidiospores from Wood-Decay Fungi Transform Laccase Substrates in the Absence of Glucose and Nitrogen Supplements

Preparations of bacterial endospores and fungal conidia are applied in biocontrols, biocatalyses, and lignocellulose fermentations. The biocatalytic abilities of basidiospores from mushrooms of the order Agaricales are unknown. To assess their potential in colonizing recalcitrant substrates solely w...

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Autores principales: Gramss, Gerhard, Voigt, Klaus-Dieter
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
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Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7345162/
https://www.ncbi.nlm.nih.gov/pubmed/32423046
http://dx.doi.org/10.3390/jof6020062
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author Gramss, Gerhard
Voigt, Klaus-Dieter
author_facet Gramss, Gerhard
Voigt, Klaus-Dieter
author_sort Gramss, Gerhard
collection PubMed
description Preparations of bacterial endospores and fungal conidia are applied in biocontrols, biocatalyses, and lignocellulose fermentations. The biocatalytic abilities of basidiospores from mushrooms of the order Agaricales are unknown. To assess their potential in colonizing recalcitrant substrates solely with their inherent resources, spores of the white-rot fungi Stropharia rugoso-annulata (Stru) and Kuehneromyces mutabilis (Kmt, Strophariaceae) were analyzed for surface-bound and internal total carbohydrates, phenols, proteins, minerals, and oxidoreductases to estimate their chemistry and the preconditions to transform the laccase substrates guaiacol and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS) independent of external glucose and nitrogen. Surfaces of Stru/Kmt spores released (mg kg(−1)) hexoses, 7300/9700; phenols, >62/220; proteins, 21/168; and laccases, 42/0–0.15 µmol ABTS(•+) kg(−1) min(−1) that mimicked oxidative activities of the resting spores. Milled-spore extracts contained pentoses, 96,600/6750; hexoses, 160,000/15,130; phenols, 452/767; protein, 12,600/924; true laccase, 688/0.30; and enzyme-protein-activating transition metals such as Cu in concentrations typical of wheat grains. Independent of external N and C supply, spores (<1‰) germinated in bideionized water, supported by their surface resources. Kmt spores germinated, too, at comparable rates in N-free solutions of glucose and the not immediately metabolizable ABTS and guaiacol. The release of proteins and oxidoreductase(s) by Kmt spores starting upon germination was higher in guaiacol-incubated idiophase- than in glucose-incubated trophophase-spores and led to the 3–4-fold formation of guaiacol polymerizates and ABTS(•+). Constitutive aromatic ring-cleaving dioxygenases in the dormant spore that could be involved in the intrinsic metabolization of guaiacol were not detected. It is concluded that intrinsic resources enable (germinating) spores to release the highly efficient laccases of basidiomycetes and to transform aromatic compounds in the absence of sugar amendments. Spores show therefore plant seed-like autonomy in nutrient modification and acquisition during the early stages of the colonization of inert substrates.
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spelling pubmed-73451622020-07-09 Basidiospores from Wood-Decay Fungi Transform Laccase Substrates in the Absence of Glucose and Nitrogen Supplements Gramss, Gerhard Voigt, Klaus-Dieter J Fungi (Basel) Article Preparations of bacterial endospores and fungal conidia are applied in biocontrols, biocatalyses, and lignocellulose fermentations. The biocatalytic abilities of basidiospores from mushrooms of the order Agaricales are unknown. To assess their potential in colonizing recalcitrant substrates solely with their inherent resources, spores of the white-rot fungi Stropharia rugoso-annulata (Stru) and Kuehneromyces mutabilis (Kmt, Strophariaceae) were analyzed for surface-bound and internal total carbohydrates, phenols, proteins, minerals, and oxidoreductases to estimate their chemistry and the preconditions to transform the laccase substrates guaiacol and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS) independent of external glucose and nitrogen. Surfaces of Stru/Kmt spores released (mg kg(−1)) hexoses, 7300/9700; phenols, >62/220; proteins, 21/168; and laccases, 42/0–0.15 µmol ABTS(•+) kg(−1) min(−1) that mimicked oxidative activities of the resting spores. Milled-spore extracts contained pentoses, 96,600/6750; hexoses, 160,000/15,130; phenols, 452/767; protein, 12,600/924; true laccase, 688/0.30; and enzyme-protein-activating transition metals such as Cu in concentrations typical of wheat grains. Independent of external N and C supply, spores (<1‰) germinated in bideionized water, supported by their surface resources. Kmt spores germinated, too, at comparable rates in N-free solutions of glucose and the not immediately metabolizable ABTS and guaiacol. The release of proteins and oxidoreductase(s) by Kmt spores starting upon germination was higher in guaiacol-incubated idiophase- than in glucose-incubated trophophase-spores and led to the 3–4-fold formation of guaiacol polymerizates and ABTS(•+). Constitutive aromatic ring-cleaving dioxygenases in the dormant spore that could be involved in the intrinsic metabolization of guaiacol were not detected. It is concluded that intrinsic resources enable (germinating) spores to release the highly efficient laccases of basidiomycetes and to transform aromatic compounds in the absence of sugar amendments. Spores show therefore plant seed-like autonomy in nutrient modification and acquisition during the early stages of the colonization of inert substrates. MDPI 2020-05-14 /pmc/articles/PMC7345162/ /pubmed/32423046 http://dx.doi.org/10.3390/jof6020062 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Gramss, Gerhard
Voigt, Klaus-Dieter
Basidiospores from Wood-Decay Fungi Transform Laccase Substrates in the Absence of Glucose and Nitrogen Supplements
title Basidiospores from Wood-Decay Fungi Transform Laccase Substrates in the Absence of Glucose and Nitrogen Supplements
title_full Basidiospores from Wood-Decay Fungi Transform Laccase Substrates in the Absence of Glucose and Nitrogen Supplements
title_fullStr Basidiospores from Wood-Decay Fungi Transform Laccase Substrates in the Absence of Glucose and Nitrogen Supplements
title_full_unstemmed Basidiospores from Wood-Decay Fungi Transform Laccase Substrates in the Absence of Glucose and Nitrogen Supplements
title_short Basidiospores from Wood-Decay Fungi Transform Laccase Substrates in the Absence of Glucose and Nitrogen Supplements
title_sort basidiospores from wood-decay fungi transform laccase substrates in the absence of glucose and nitrogen supplements
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7345162/
https://www.ncbi.nlm.nih.gov/pubmed/32423046
http://dx.doi.org/10.3390/jof6020062
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