Black yeasts in cold habitats

Black yeasts have already been known since the end of the nineteenth century, but for a number of reasons, only few workers were familiar with them. That was since recently, until the wealth of biodiversity, stunning ecologies and potential applications have become apparent. Some remote and extreme locations, such as mountain tops, glaciers or polar areas, are now being investigated by mycologists. Many rock-colonizing fungi have been interpreted for long time as blackish fly-ash particles or dust on marble monuments or buildings. Black yeasts are easily overlooked in routine studies due to their very slow growth and poor competitive abilities. With the improvement isolation procedures, it has become clear that black yeasts are actually much more common and widespread than previously believed. Identification was hampered by their morphological plasticity, until molecular techniques became a routine approach in fungal systematic. In this chapter, the authors aim to give an overview of all the aspects concerning this unconventional group of fungi, from their peculiar ecology to their wide spectrum of biodiversity. Understanding about their ecological amplitude arose from impressive efforts in sampling remote habitats and concomitant sequencing activity during the last two decades.