Abstract

Lichens are currently interpreted as complex self-sustaining ecosystems formed by the interaction of the primary symbionts and other microorganisms. These microorganisms, which colonize the surface of lichen thalli, could be crucial actors in nutrient cycling. Here, we used PICRUSt2 to predict and compare the potential functions of bacteria closely associated with Peltigera frigida thalli and their substrates. We found that these bacteria could potentially transform organic and inorganic molecules related to nitrogen, phosphorus, and sulfur cycles. Although further experiments to verify these potential contributions are required, these results reinforce the proposal of the nutrient-cycling role of bacteria associated with P. frigida.