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Lichenihabitans psoromatis gen. nov., sp. nov., a member of a novel lineage (Lichenihabitantaceae fam. nov.) within the order of Rhizobiales isolated from Antarctic lichen

2019-12-01T00:00:00Z

Title: Lichenihabitans psoromatis gen. nov., sp. nov., a member of a novel lineage (Lichenihabitantaceae fam. nov.) within the order of Rhizobiales isolated from Antarctic lichen Authors: Noh, Hyun-Ju; Baek, Kiwoon; Hwang, Chung Yeon; Shin, Seung Chul; Hong, Soon Gyu; Lee, Yung Mi Abstract: Two Gram-stain-negative, facultative anaerobic chemoheterotrophic, pink-coloured, rod-shaped and non-motile bacterial strains, PAMC 29128 and PAMC 29148(T), were isolated from lichen. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that strains PAMC 29128 and PAMC 29148(T) belong to lichen-associated Rhizobiales-1 (LAR1), an uncultured phylogenetic lineage of the order Rhizobiales and the most closely related genera were Methylocapsa (<93.9 %) and Methylosinus (<93.8 %). The results of phylogenomic and genomic relatedness analyses also showed that strains PAMC 29128 and PAMC 29148(T) were clearly distinguished from other species in the order Rhizobiales with average nucleotide identity values of <71.4% and genome-to-genome distance values of <22.7 %. Genomic analysis revealed that strains PAMC 29128 and PAMC 29148(T) did not contain genes involved in atmospheric nitrogen fixation or utilization of carbon compounds such as methane and methanol. Strains PAMC 29128 and PAMC 29148(T) were able to utilize certain monosaccharides, disaccharides, sugar alcohols and other organic compounds as a sole carbon source. The major fatty acids (>10%) were summed feature 8 (C-18:1 omega 7c and/or C-18:1 omega 6c; 33.7-39.7 %), summed feature 3 (C-16:1 omega 7c and/or C-16(:1) omega 6c; 25.2-254%) and C-19:0 cyclo omega 8c (11.9-15.4%). The major respiratory quinone was Q-10. The genomic DNA G+C contents of PAMC 29128 and PAMC 29148(T) were 63.0 and 63.1 mol%, respectively. Their distinct phylogenetic position and some physiological characteristics support the proposal of Lichenihabitans gen. nov., with the type species Lichenihabitans psoromatis sp. nov. (type strain, PAMC 29148(T)=KCCM 43293(T)=JCM 33311(T)). Lichenihabitantaceae fam. nov. is also proposed.

Local-scale variation of soil bacterial communities in ice-free regions of maritime Antarctica

2019-03-01T00:00:00Z

Title: Local-scale variation of soil bacterial communities in ice-free regions of maritime Antarctica Authors: Kim, Mincheol; Lim, Hyun-Soo; Hyun, Chang-Uk; Cho, Ahnna; Noh, Hyun-Ju; Hong, Soon Gyu; Kim, Ok-Sun Abstract: The majority of biogeographic studies in Antarctic terrestrial ecosystems have focused on macroscopic eukaryote taxa. In contrast, microbial taxa have been almost neglected or examined without sufficient spatial coverage. Here, we examined the spatial distribution of soil bacterial communities and their relation to local environmental gradients in ice-free regions of the maritime Antarctic. Soils in this region were dominated by Actinobacteria and Proteobacteria, which are typically found in Antarctic soils. Notably, candidate divisions AD3 and WPS-2, which rarely occur in other biomes, were found in high abundance in acidic surface soils. Soil pH and total organic carbon (TOC) were the primary drivers of the bacterial community structure and various geochemical variables also played important roles in structuring bacterial community composition. Bacterial communities were significantly correlated to measured environmental variables, most of which are spatially structured at the local spatial scale (0.5？8 km). This suggests that spatial heterogeneity of environmental factors is an important driver of shifts in bacterial communities. Although various sets of environmental variables were related to bacterial communities, a large proportion of community variation remained unexplained. This indicates that bacterial communities in Antarctic soils may be governed by other biotic or abiotic factors which are not typically measured in other biome studies.

Psoroma antarcticum, a new lichen species from Antarctica and neighbouring areas

2018-01-01T00:00:00Z

Title: Psoroma antarcticum, a new lichen species from Antarctica and neighbouring areas Authors: Park, Chae Haeng; Hong, Soon Gyu; ARVE ELVEBAKK Abstract: Icefree, terrestrial, Antarctic ecosystems have a polar desert-like appearance with a scarce vegetation cover, completely dominated by bryophytes and lichens. Knowledge of the rich Antarctic lichen biodiversity, including c. 400 species, is therefore necessary, also for studies of other ecosystem components. The genus Psoroma is partly dominant there, and own ongoing research indicates that many of its members have been misunderstood. The aim of the present study is to describe Psoroma antarcticum as new to science, study its habitat ecology and total distribution, and include a genetic analysis with respect to its internal variation and relationship to other species. The species differs from the closely related species Psoroma hypnorum, in having distinctly cup-shaped apothecia with thalline excipuli without squamules and tomentose lower sides, in having shorter ascospores without apical nodulose extensions and thalli with grey-to-black melanins. It is shown to form a monophyletic clade based on an analysis of the ITS, LSU, and mtSSU loci, and this clade is included in the Psoroma s. str. clade, which includes P. hypnorum, Psoroma paleaceum, Psoroma buchananii, and Psoroma fruticulosum with high statistical support. The new species has its main distribution in the maritime South Shetland and South Orkney Islands of Antarctica, and most samples originate from King George Island, where it is common and an important component in polar desert-like vegetation. Scattered occurrences have also been found in Chilean Tierra del Fuego, South Georgia, and Bouvet Island.

Endophytic and endolichenic fungal diversity in maritime Antarctica based on cultured material and their evolutionary position among Dikarya

2018-01-01T00:00:00Z

Title: Endophytic and endolichenic fungal diversity in maritime Antarctica based on cultured material and their evolutionary position among Dikarya Authors: N.H. Yu; J.-S. Hur; P.K. Divakar; M. Talavera; Hong, Soon Gyu; S.-O. Oh; M.-H. Jeong; C.-H. Park; J.A. Kim; S.-Y. Park Abstract: Fungal endophytes comprise one of the most ubiquitous groups of plant symbionts. They live asymptomatically within vascular plants, bryophytes and also in close association with algal photobionts inside lichen thalli. While endophytic diversity in land plants has been well studied, their diversity in lichens and bryophytes are poorly understood. Here, we compare the endolichenic and endophytic fungal communities isolated from lichens and bryophytes in the Barton Peninsula, King George Island, Antarctica. A total of 93 fungal isolates were collected from lichens and bryophytes. In order to determine their identities and evolutionary relationships, DNA sequences of the nuclear internal transcribed spacer (ITS), nuclear ribosomal small subunit (nuSSU), nuclear large subunit (nuLSU), and mitochondrial SSU (mtSSU) rDNA were obtained and protein coding markers of the two largest subunit of RNA polymerase II (RPB1 and RPB2) were generated. Multilocus phylogenetic analyses revealed that most of the fungal isolates were distributed in the following six classes in the phylum Ascomycota: Dothideomycetes, Eurotiomycetes, Lecanoromycetes, Leotiomycetes, Pezizomycetes and Sordariomycetes. For the first time we report the presence of subphylum Mortierellomycotina that may belong to an undescribed order in endophytic fungi. Taken together, our results imply that lichens and bryophytes provide similar niches and harbour a selection of these fungi, indicating generalists within the framework of evolutionary adaptation.