Experimental evolution of stress-tolerant fungi at extreme water activity

Hariri Akbari, Farhad (author), Gostinčar, Cene (mentor), Gunde Cimerman, Nina (comentor)

This research delves into extremotolerant fungi's responses to stress, particularly focusing on halotolerant black yeasts and a halophilic basidiomycete. After subjecting them to 12 cultivation cycles at NaCl or glycerol concentrations near their growth limits, evolved strains exhibited accelerated growth rates, driven by hundreds of identified single nucleotide polymorphisms (SNPs). Notably, distinct gene groups, such as voltage-gated potassium channels in Aureobasidium pullulans and hydrophobins in Wallemia ichthyophaga, were implicated in adaptation to high salinity. Optimized glycerol management was observed, crucial for osmotic pressure balance. This study contributes novel insights into fungal adaptation, highlighting the broader significance of salinity as a stressor. Leveraging bioinformatics methods, the research underscores the potential of extremotolerant fungi in various fields, including biotechnology.

• Language: English
• Keywords: experimental evolution, extremophile, halotolerance, genome, glycerol, adaptation, black yeasts, basidiomycete, molecular mechanisms, bioinformatics
• Work type: Doctoral dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: BF - Biotechnical Faculty
• Year: 2025
• PID: 20.500.12556/RUL-169503
• COBISS.SI-ID: 237922307
• Publication date in RUL: 30.05.2025

Secondary language

• Language: Slovenian
• Title: Eksperimentalna evolucija na stres tolerantnih gliv pri ekstremni vodni aktivnosti

Abstract

Ta raziskava obravnava odzive ekstremotolerantnih gliv na stres, s poudarkom na izbranih halotolerantnih črnih kvasovkah in halofilni bazidiomicetni glivi. Ko smo le-te izpostavili 12 ciklom gojenja pri koncentracijah NaCl ali glicerola blizu njihovih meja za rast, so razvile pospešeno rast in v genomih nakopičile več sto polimorfizmov posameznih nukleotidov (SNP). Pri prilagajanju gliv na visoko slanost so sodelovale različne skupine genov, kot so geni za napetostno odvisne kalijeve kanalčke pri kvasovki Aureobasidium pullulans in geni za hidrofobine pri vrsti Wallemia ichthyophaga. Opazili smo spremenjene znotraj- in zunajcelične koncentracije glicerola, ki je ključnega pomena za uravnavanje osmotskega tlaka. Ta raziskava ponuja nova spoznanja o prilagajanju gliv in poudarja širši pomen slanosti kot abiotskega vira stresa. Z uporabo bioinformacijskih metod raziskava poudarja potencial ekstremno tolerantnih gliv na različnih področjih, vključno z biotehnologijo.

• Keywords: eksperimentalna evolucija, ekstremofil, halotoleranca, genom, glicerol, prilagoditev, črne kvasovke, bazidiomicete, molekularni mehanizmi, bioinformatika