Mortierellaceae from subalpine and alpine habitats: new species of Entomortierella, Linnemannia, Mortierella, Podila and Tyroliella gen. nov.

Abstract

Fungi are incredibly diverse, but they are unexplored, especially in the subalpine and alpine zone. Mortierellaceae are certainly one of the most abundant, species-rich, and widely distributed cultivable soil fungal families in terrestrial habitats, including subalpine and alpine zones. The phylogeny of Mortierellaceae was recently resolved based on current state of the art molecular techniques, and the paraphyletic genus Mortierella sensu lato (s.l.) was divided into 13 monophyletic genera. Our extensive sampling campaigns in the Austrian Alps resulted in 139 different Mortierellaceae pure culture isolates representing 13 new species. For the definition of taxa, we applied both classical morphological criteria, as well as modern DNA-based methods. Phylogenetic relationships were resolved based on the ribosomal DNA internal transcribed spacer (rDNA ITS), the large subunit (LSU), and the DNA-directed RNA polymerase II largest subunit 1 (RPB1). In this study, we proposed a new genus and described 13 new species belonging to the genera Entomortierella, Linnemannia, Mortierella and Podila. In addition, we proposed eight new combinations, re-defined E. jenkinii at species level, defined a neotype for M. alpina and lecto- as well as epitypes for M. fatshederae, M. jenkinii, and M. longigemmata. The rDNA ITS region is generally applied as classical barcoding gene for fungi. However, the obtained phylogenetic resolution is often too low for an accurate identification of closely related species of Mortierellaceae, especially for small sampling sizes. In such cases, unambiguous identification can be obtained based on morphological characters of pure culture isolates. Therefore, we also provide dichotomous keys for species identification within phylogenetic lineages.

Fungal and bacterial communities and their associations in snow-free and snow covered (sub-)alpine Pinus cembra forest soils

“…Many ectomycorrhizal fungi are Basidiomycota, which particularly colonize the roots of their host plants during the growing season [ 12 ]. Saprobic Mortierellomycotina accounted for a high abundance throughout the year, which is likely owed to their high abundance in (sub-)alpine ecosystems [ 79 , 80 ]. They can grow at low temperatures [ 79 ], which explains their high association frequency under snow cover.…”

“…Saprobic Mortierellomycotina accounted for a high abundance throughout the year, which is likely owed to their high abundance in (sub-)alpine ecosystems [ 79 , 80 ]. They can grow at low temperatures [ 79 ], which explains their high association frequency under snow cover. Their higher association frequency under snow covered compared to snow-free soil suggests that bacteria might contribute to the competitive advantage Mortierellomycotina appear to have under these conditions.…”

“…Solibacter associations indicates a potential role of the plant in this association, thereby making it a good candidate to study tri- or multipartite interactions. In (sub-)alpine ecosystems, Mortierella is an important part of the core microbiome, which is active under snow cover [ 47 , 79 ]. It is very likely that Mortierella and associated bacteria synergistically colonize soil habitats, and that metabolic products, like fatty acids produced by Mortierella, serve as substrates for associated bacteria.…”

A Second Fungal Outbreak in Castañar Cave, Spain, Discloses the Fragility of Subsurface Ecosystems

“…Mortierella spp. are considered important members of the soil core microbial community [ 34 ]. Ten species of Mortierella were retrieved in Castañar Cave, but only two of them ( M. alpina and Mortierella sp.)…”

Don’t let valuable microbiome data go to waste: combined usage of merging and direct-joining of sequencing reads for low quality amplicon data

“…The genus Linnemannia was previously known asMortierella , which was a part of the mock community. Earlier ITS sequence based phylogenetic studies clustered the Linnemanniaspecies with Mortierella species (Telagathoti et al, 2022;Wagner et al, 2013). The ASVs belonging to the Linnemanniaspecies was included in the BLAST search, which clarified the taxonomy as Mortierella sp.…”