Experimental evolution of extremotolerant and extremophilic fungi under osmotic stress

Hariri Akbari, Farhad (author), Song, Zewei (author), Turk, Martina (author), Gunde-Cimerman, Nina (author), Gostinčar, Cene (author)

Experimental evolution was carried out to investigate the adaptive responses of extremotolerant fungi to a stressful environment. For 12 cultivation cycles, the halotolerant black yeasts Aureobasidium pullulans and Aureobasidium subglaciale were grown at high NaCl or glycerol concentrations, and the halophilic basidiomycete Wallemia ichthyophaga was grown close to its lower NaCl growth limit. All evolved Aureobasidium spp. accelerated their growth at low water activity. Whole genomes of the evolved strains were sequenced. No aneuploidies were detected in any of the genomes, contrary to previous studies on experimental evolution at high salinity with other species. However, several hundred single-nucleotide polymorphisms were identified compared with the genomes of the progenitor strains. Two functional groups of genes were overrepresented among the genes presumably affected by single-nucleotide polymorphisms: voltage-gated potassium channels in A. pullulans at high NaCl concentration, and hydrophobins in W. ichthyophaga at low NaCl concentration. Both groups of genes were previously associated with adaptation to high salinity. Finally, most evolved Aureobasidium spp. strains were found to have increased intracellular and decreased extracellular glycerol concentrations at high salinity, suggesting that the strains have optimised their management of glycerol, their most important compatible solute. Experimental evolution therefore not only confirmed the role of potassium transport, glycerol management, and cell wall in survival at low water activity, but also demonstrated that fungi from extreme environments can further improve their growth rates under constant extreme conditions in a relatively short time and without large scale genomic rearrangements.

• Language: English
• Keywords: experimental evolution, extremophile, halotolerance, black yeast, adaptation, genome, glycerol
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: Str. 617-631
• Numbering: Vol. 76, iss. 9
• PID: 20.500.12556/RUL-160786-2e0d6d12-a3d9-3a70-77ab-27d954acfabb
• UDC: 57
• ISSN on article: 1521-6543
• DOI: 10.1002/iub.2825
• COBISS.SI-ID: 193830147
• Publication date in RUL: 04.09.2024

Record is a part of a journal

• Title: IUBMB life
• Publisher: Taylor & Francis
• ISSN: 1521-6543
• COBISS.SI-ID: 14540327

Licences

• License: CC BY-NC 4.0, Creative Commons Attribution-NonCommercial 4.0 International
• Link: http://creativecommons.org/licenses/by-nc/4.0/
• Description: A creative commons license that bans commercial use, but the users don’t have to license their derivative works on the same terms.

Secondary language

• Language: Slovenian
• Keywords: eksperimentalna evolucija, ekstremofil, halotoleranca, črna kvasovka, prilagoditev