Diversity of bacteria associated with lichens in Mt. Yunmeng in Beijing, China

Lichens host highly diverse and complex microbial communities, which may perform essential functions in the symbiotic ecosystems. In this study, sequencing of 16S rRNA was used to investigate the bacterial communities associated with lichens of two growth forms (foliose and crustose). Results showed that Cyanobacteria, Pseudomonadota, Actinomycetota and Acidobacter were dominant phyla in both types of lichens, while Acetobacterales and Hyphomicrobiales were the dominant orders. Alpha diversity index showed that the richness of bacteria hosted by foliose lichens was significantly higher than that by crustose ones, and PCoA results showed a significant difference between beta diversity of the foliose lichen-associated bacterial communities and that of crustose lichen-associated ones. It can be inferred that the growth form of lichens is the most important factor affecting their associated bacterial communities, and the host species comes next, while altitude is even less important. It is proposed that the microbial communities play important roles in fixing nitrogen, providing nutrition, and curbing harmful microorganisms, therefore are an integrated and indispensable part of lichens, and together they form a self-sufficient ecosystem.