The Microbiomes of Seven Lichen Genera Reveal Host Specificity, a Reduced Core Community and Potential as Source of Antimicrobials

Abstract

The High Andean Paramo ecosystem is a unique neotropical mountain biome considered a diversity and evolutionary hotspot. Lichens, which are complex symbiotic structures that contain diverse commensal microbial communities, are prevalent in Paramos. There they play vital roles in soil formation and mineral fixation. In this study we analyzed the microbiomes of seven lichen genera in Colombian Paramos using 16S rRNA gene amplicon sequencing and provide the first description of the bacterial communities associated with Cora and Hypotrachyna lichens. Paramo lichen microbiomes varied in diversity indexes and number of OTUs, but were composed predominantly by the phyla Acidobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, Proteobacteria, and Verrucomicrobia. In the case of Cora and Cladonia, the microbiomes were distinguished based on the identity of the lichen host. While the majority of the lichen-associated microorganisms were not present in all lichens sampled, sixteen taxa shared among this diverse group of lichens suggest a core lichen microbiome that broadens our concept of these symbiotic structures. Additionally, we identified strains producing compounds active against clinically relevant microbial strains. These results indicate that lichen microbiomes from the Paramo ecosystem are diverse and host-specific but share a taxonomic core and can be a source of new bacterial taxa and antimicrobials.

Multidisciplinary approach to describe Trebouxia diversity within lichenized fungi Buellia zoharyi from the Canary Islands

“…g . Aschenbrenner et al 2014;Grube et al 2015;Cernava et al 2017;Sierra et al 2020) and photosynthetic green microalgae co-inhabit within the lichen thalli, giving rise to the peculiar phenotypes, and which may contribute to the diverse patterns of secondary metabolites (Spribille 2018) and environmental adaptation. In terms of lichen photobionts, intrathalline microalgal diversity, e.g.…”

Symbiotic microalgal diversity within lichenicolous lichens and crustose hosts on Iberian Peninsula gypsum biocrusts

“…They have traditionally been considered the symbiotic phenotype resulting from the interactions of a single fungal partner and one or a few photosynthetic partners. However, lichen symbiosis has been shown to be far more complex and may include a wide range of other interacting organisms, including nonphotosynthetic bacteria, accessory fungi, and algae 3 , 4 .…”

Geography, not host identity, shapes bacterial community in reindeer lichens

“…Genomic exploration of lichen associated microbes has revealed an unexpected diversity of bacteria, the majority belonging to Alphaproteobacteria (Cardinale et al ., 2008; Grube and Berg, 2009; Hodkinson and Lutzoni, 2009; Bates et al ., 2011; Printzen et al ., 2012). Lichen bacteriota contribute to essential functions of host (nutrient supply, resistance against biotic and abiotic factors, growth support, detoxification of metabolites or provision of vitamin B 12 ) (Grube et al ., 2015) and, can be determine by different factors such as host-identity (Bates et al ., 2011; Sierra et al ., 2020), photoautotrophic symbiont (Hodkinson et al ., 2012), thallus conditions (Mushegian et al ., 2011; Cardinale, Steinová, et al ., 2012; Noh et al ., 2020) and growth form (Park et al ., 2016), substrate type (Park et al ., 2016), habitat (Cardinale, Grube, et al ., 2012), or geography (Hodkinson and Lutzoni, 2009; Aschenbrenner et al ., 2014). To date, lichen microbiomes studies have been mainly carried out in Lobaria pulmonaria (Cardinale, Grube, et al ., 2012; Aschenbrenner et al ., 2014), Cetraria acuelata (Printzen et al ., 2012), Cladonia arbuscula (Cardinale et al ., 2008) or C. squamosa (Noh et al ., 2020).…”