Antarctic lichen bacteriome

Lichens are especially successful in Antarctica, where they have adapted to the harsh climateand diversified, with over 400 lichen species found thriving in this region, exhibiting a verystrong specialization toward certain habitat types and participate in a successivecolonization of barren land left by receding glaciers. This success is predominantly due to the components that make up a lichen and their activity: the heterotrophic fungus, the photoautotrophic partner, as well as themicrobiome inhabiting the lichen. While the physiology and role of the fungal andphotoautotrophic algal/cyanobacterial counterparts are known, the diversity of themicrobiome, (more precisely the bacteriome) and its contribution to the lichen symbiosisremains uncertain Thus, the aim of this research was to demonstrate the relation betweenthe Antarctic lichen hosted bacterial communities and nutrient amounts in close lichenproximity, the lichen thalli age, as well as the lichen itself. With this, the followinghypotheses were checked: (i) the lichen hosted bacterial microbiome structure is speciesspecific, regardless of the lichen habitat ( specialist lichens (nitrophilic and nitrophobic)rely on a fixed subset of bacterial groups that is low in diversity, while generalist lichens(N tolerant) contain a large, diverse bacterial community, with certain bacterial groupsdisplaying activity depending on the environmental conditions ( the microbiomestructure and function change according to the lichen thalli age; the community graduallyincreases in metabolic activity, abundance and phylogenetic diversity.