Diversity of endophytic bacterial and fungal microbiota associated with the medicinal lichen Usnea longissima at high altitudes

Abstract

Endophytic microbial communities of lichen are emerging as novel microbial resources and for exploration of potential biotechnological applications. Here, we focused on a medicinal lichen Usnea longissima, and investigated its bacterial and fungal endophytes. Using PacBio 16S rRNA and ITS amplicon sequencing, we explored the diversity and composition of endophytic bacteria and fungi in U. longissima collected from Tibet at five altitudes ranging from 2,989 to 4,048 m. A total of 6 phyla, 12 classes, 44 genera, and 13 species of the bacterial community have been identified in U. longissima. Most members belong to Alphaproteobacteria (42.59%), Betaproteobacteria (33.84%), Clostridia (13.59%), Acidobacteria (7%), and Bacilli (1.69%). As for the fungal community, excluding the obligate fungus sequences, we identified 2 phyla, 15 classes, 65 genera, and 19 species. Lichen-related fungi of U. longissima mainly came from Ascomycota (95%), Basidiomycota (2.69%), and unidentified phyla (2.5%). The presence of the sequences that have not been characterized before suggests the novelty of the microbiota. Of particular interest is the detection of sequences related to lactic acid bacteria and budding yeast. In addition, the possible existence of harmful bacteria was also discussed. To our best knowledge, this is the first relatively detailed study on the endophytic microbiota associated with U. longissima. The results here provide the basis for further exploration of the microbial diversity in lichen and promote biotechnological applications of lichen-associated microbial strains.

Fungal Diversity Associated with Thirty-Eight Lichen Species Revealed a New Genus of Endolichenic Fungi, Intumescentia gen. nov. (Teratosphaeriaceae)

“…Still, it is important to conduct culture-based studies, such as this. Isolates recovered from this study and from other similar studies [26,27,60] will allow us to thoroughly investigate the biology of these fungi. In addition to this, some endolichenic fungi can also be of biotechnological importance, such as oleaginous yeasts [24].…”

“…Globally, studies involving endolichenic fungi led to the identification and discovery of various new and previously identified fungal taxa representing various lineages of Ascomycota, such as Pezizomycetes, Dothideomycetes, Eurotiomycetes, Leotiomycetes, and Sordariomycetes, among others [20][21][22][23]. Echoing the global trend, several novel endolichenic fungal taxa were also identified in China [24][25][26][27][28]. In a recent fungal biodiversity study by Xu et al (2022), the authors detected a substantial diversity of endolichenic fungi in the family Teratosphaeriaceae from Heterodermia obscurata, and proposed that Teratosphaeriaceae is likely to be one of the core endophytic fungal families associated with this lichen [13].…”

Host selection tendency of key microbiota in arid desert lichen crusts

“…In this study we could show that the alpha diversity of bacteria decreased from soil toward lichen samples (Figure 1A ), but because there is no description work about alpha diversity on lichen growth different partition, we can't compare our results with existing lichen literature. What the slightly related studies reported the lichen bacterial community structure at different growth stages, geographical flora, and growth substrates, and so forth [ 20 , 34 , 35 , 36 ]. Although the bacterial microbiota is considered of importance for the holobiome, there have so far only been microscopic observations of differences between upper and lower surfaces of lichens [ 12 ].…”