The biology of black yeast genomes

In this PhD thesis, the whole genomes of black yeast-like fungi belonging to the order Chaetothyriales (division Ascomycetes) and filamentous relatives are sequenced and examined in order to understand the mechanisms behind their adaptation to diverse ecological niches. Chaetothyriales are able to inhabit a wide range of habitats varying from oligotrophic environments, which provide very low levels of nutrients, to sites containing complex carbon substrates. Although human infections caused by black yeasts and their filamentous relatives are considered to be rare, recalcitrant infections in patients with immunodeficiency disorders but also otherwise healthy people have consistently been reported. Their outstanding metabolic plasticity, and concomitant broad ability to degrade a variety of substrates, has generally been taken to be the reason for the diversity of places occupied by this group of fungi. Results described in this thesis provide deeper understanding of the genetic basis and potential adaptations that led the Chaetothyriales to master sites rarely colonized by other fungal species.