Regional Mountain Conference

Mortierellaceae are a family of filamentous, soil-inhabiting fungi, occurring in almost all terrestrial habitats and are an essential part of the core soil microbiome. In recent years, the diversity and distribution of Mortierellaceae in alpine habitats is becoming an increasing research focal point. Many species within the Mortierellaceae family can inhabit harsh, highly exposed, and nutrient-depleted environments including glacier forefields. These fungi are proposed to play a crucial role in habitat succession and soil development in the earliest stages. However, the ecological diversity of Mortierellaceae in the European Alps largely remains undescribed and further research is necessary in order to characterize and preserve life that is threatened by vanishing environments.

In our study, we could isolate multiple fungal strains belonging to a previously unknown Mortierellaceae taxon from two recently deglaciated calcareous glacier forefields (Italy: Marmolada, Austria: Dachstein). This novel taxon was comprehensively investigated via physiological tests, the detection of associated bacteria, macroscopical, and microscopical characterization (e.g., light, fluorescence, and scanning electron microscopy). Whole-genome sequencing and phylogenomic analyses were used to position this taxon within the Mortierellaceae family.

We could show that the isolated strains represent a novel species within a so far undescribed genus, exhibiting very distinct morphological traits. Due to the ability of this lineage to live hidden in calcareous sediments of the earliest soil developmental stages at glacier forefields, we propose the name Cryptocalciella humilis Mandolini, Szedlacsek & Peintner.