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Glycerol enhances fungal germination at the water‐activity limit for life
For the most‐extreme fungal xerophiles, metabolic activity and cell division typically halts between 0.700 and 0.640 water activity (approximately 70.0–64.0% relative humidity). Here, we investigate whether glycerol can enhance xerophile germination under acute water‐activity regimes, using an exper...
Autores principales: | , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley and Sons Inc.
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5363249/ https://www.ncbi.nlm.nih.gov/pubmed/27631633 http://dx.doi.org/10.1111/1462-2920.13530 |
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author | Stevenson, Andrew Hamill, Philip G. Medina, Ángel Kminek, Gerhard Rummel, John D. Dijksterhuis, Jan Timson, David J. Magan, Naresh Leong, Su‐Lin L. Hallsworth, John E. |
author_facet | Stevenson, Andrew Hamill, Philip G. Medina, Ángel Kminek, Gerhard Rummel, John D. Dijksterhuis, Jan Timson, David J. Magan, Naresh Leong, Su‐Lin L. Hallsworth, John E. |
author_sort | Stevenson, Andrew |
collection | PubMed |
description | For the most‐extreme fungal xerophiles, metabolic activity and cell division typically halts between 0.700 and 0.640 water activity (approximately 70.0–64.0% relative humidity). Here, we investigate whether glycerol can enhance xerophile germination under acute water‐activity regimes, using an experimental system which represents the biophysical limit of Earth's biosphere. Spores from a variety of species, including Aspergillus penicillioides, Eurotium halophilicum, Xerochrysium xerophilum (formerly Chrysosporium xerophilum) and Xeromyces bisporus, were produced by cultures growing on media supplemented with glycerol (and contained up to 189 mg glycerol g dry spores(−1)). The ability of these spores to germinate, and the kinetics of germination, were then determined on a range of media designed to recreate stresses experienced in microbial habitats or anthropogenic systems (with water‐activities from 0.765 to 0.575). For A. penicillioides, Eurotium amstelodami, E. halophilicum, X. xerophilum and X. bisporus, germination occurred at lower water‐activities than previously recorded (0.640, 0.685, 0.651, 0.664 and 0.637 respectively). In addition, the kinetics of germination at low water‐activities were substantially faster than those reported previously. Extrapolations indicated theoretical water‐activity minima below these values; as low as 0.570 for A. penicillioides and X. bisporus. Glycerol is present at high concentrations (up to molar levels) in many types of microbial habitat. We discuss the likely role of glycerol in expanding the water‐activity limit for microbial cell function in relation to temporal constraints and location of the microbial cell or habitat. The findings reported here have also critical implications for understanding the extremes of Earth's biosphere; for understanding the potency of disease‐causing microorganisms; and in biotechnologies that operate at the limits of microbial function. |
format | Online Article Text |
id | pubmed-5363249 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | John Wiley and Sons Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-53632492017-04-06 Glycerol enhances fungal germination at the water‐activity limit for life Stevenson, Andrew Hamill, Philip G. Medina, Ángel Kminek, Gerhard Rummel, John D. Dijksterhuis, Jan Timson, David J. Magan, Naresh Leong, Su‐Lin L. Hallsworth, John E. Environ Microbiol Research Articles For the most‐extreme fungal xerophiles, metabolic activity and cell division typically halts between 0.700 and 0.640 water activity (approximately 70.0–64.0% relative humidity). Here, we investigate whether glycerol can enhance xerophile germination under acute water‐activity regimes, using an experimental system which represents the biophysical limit of Earth's biosphere. Spores from a variety of species, including Aspergillus penicillioides, Eurotium halophilicum, Xerochrysium xerophilum (formerly Chrysosporium xerophilum) and Xeromyces bisporus, were produced by cultures growing on media supplemented with glycerol (and contained up to 189 mg glycerol g dry spores(−1)). The ability of these spores to germinate, and the kinetics of germination, were then determined on a range of media designed to recreate stresses experienced in microbial habitats or anthropogenic systems (with water‐activities from 0.765 to 0.575). For A. penicillioides, Eurotium amstelodami, E. halophilicum, X. xerophilum and X. bisporus, germination occurred at lower water‐activities than previously recorded (0.640, 0.685, 0.651, 0.664 and 0.637 respectively). In addition, the kinetics of germination at low water‐activities were substantially faster than those reported previously. Extrapolations indicated theoretical water‐activity minima below these values; as low as 0.570 for A. penicillioides and X. bisporus. Glycerol is present at high concentrations (up to molar levels) in many types of microbial habitat. We discuss the likely role of glycerol in expanding the water‐activity limit for microbial cell function in relation to temporal constraints and location of the microbial cell or habitat. The findings reported here have also critical implications for understanding the extremes of Earth's biosphere; for understanding the potency of disease‐causing microorganisms; and in biotechnologies that operate at the limits of microbial function. John Wiley and Sons Inc. 2016-11-13 2017-03 /pmc/articles/PMC5363249/ /pubmed/27631633 http://dx.doi.org/10.1111/1462-2920.13530 Text en © 2016 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd This is an open access article under the terms of the Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Articles Stevenson, Andrew Hamill, Philip G. Medina, Ángel Kminek, Gerhard Rummel, John D. Dijksterhuis, Jan Timson, David J. Magan, Naresh Leong, Su‐Lin L. Hallsworth, John E. Glycerol enhances fungal germination at the water‐activity limit for life |
title | Glycerol enhances fungal germination at the water‐activity limit for life |
title_full | Glycerol enhances fungal germination at the water‐activity limit for life |
title_fullStr | Glycerol enhances fungal germination at the water‐activity limit for life |
title_full_unstemmed | Glycerol enhances fungal germination at the water‐activity limit for life |
title_short | Glycerol enhances fungal germination at the water‐activity limit for life |
title_sort | glycerol enhances fungal germination at the water‐activity limit for life |
topic | Research Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5363249/ https://www.ncbi.nlm.nih.gov/pubmed/27631633 http://dx.doi.org/10.1111/1462-2920.13530 |
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