Fungal communities associated to three epiphytic lichens active against Candida, were investigated using culture-based methods We hypothetized that associated fungi would contribute to lichens activities. The ability of specific fungi to grow inside or outside lichens was investigated. To detect biogenesis pathways involved in the production of secondary metabolites, genes coding for nonribosomal peptide synthetase (NRPS) and polyketide synthase I (PKS I) were screened by PCR from fungal DNA extracts. Both endo and epilichenic communities were isolated from two fructicose (Evernia prunastri and Ramalina fastigiata) and one foliose (Pleurosticta acetabulum) lichens. A total of 86 endolichenic and 114 epilichenic isolates were obtained, corresponding to 18 and 24 phylogenetic groups respectively suggesting a wide diversity of fungi. The communities and the species richness were distinct between the three lichens which hosted potentially new fungal species. Additionally, the endo- and epilichenic communities differed in their composition: Sordariomycetes were particularly abundant among endolichenic fungi and Dothideomycetes among epilichenic fungi. Only a few fungi colonized both habitats, such as S. fimicola, Cladosporium sp1 and Botrytis cinerea. Interestingly, Nemania serpens (with several genotypes) was the most abundant endolichenic fungus (53% of isolates) and was shared by the three lichens. Finally, 12 out of 36 phylogenetic groups revealed the presence of genes coding for nonribosomal peptide synthetase (NRPs) and polyketide synthase I (PKS I). This study shows that common lichens are reservoirs of diverse fungal communities, which could potentially contribute to global activity of the lichen and, therefore, deserve to be isolated for further chemical studies.

使用基于文化的方法调查了与三个对抗念珠菌的附生地衣相关的真菌群落。我们假设相关真菌将有助于地衣活动。研究了特定真菌在地衣内部或外部生长的能力。为了检测涉及次级代谢产物产生的生物发生途径，通过PCR从真菌DNA提取物中筛选了编码非核糖体肽合成酶（NRPS）和聚酮化合物合酶I（PKS I）的基因。从两个果糖（Evernia prunastri和Ramalina fastigiata）和一个叶糖（Pleurosticta acetabulum ）中分离出内生和附生群落）地衣。总共获得了86种内地分离菌和114种上皮分离菌，分别对应于18个和24个系统发生类群，表明真菌的多样性很大。这三个地衣之间的群落和物种丰富度截然不同，这三个地衣可能是新的真菌物种。此外，内生和附生菌群落的组成也不同：内生真菌中的Sordariomycetes尤其丰富，而附生真菌中的Dothideomycetes尤其丰富。在这两个生境中只有少数真菌定居，例如金线虫，Cladosporium sp1和灰葡萄孢。有趣的是，Nemania serpens（具有几种基因型）是最丰富的苔藓内生真菌（占分离株的53％），由三个地衣所共有。最后，在36个系统发育组中，有12个发现存在编码非核糖体肽合成酶（NRPs）和聚酮化合物合酶I（PKS I）的基因。这项研究表明，普通的地衣是各种真菌群落的储藏地，它们可能会促进地衣的全球活动，因此，有必要对其进行进一步的化学研究以进行分离。