This study assessed the diversity and distribution of fungal communities in eight marine sediments of Kongsfjorden (Svalbard, High Arctic) using 454 pyrosequencing with fungal-specific primers targeting the internal transcribed spacer (ITS) region of the ribosomal rRNA gene. Sedimentary fungal communities showed high diversity with 42,219 reads belonging to 113 operational taxonomic units (OTUs). Of these OTUs, 62 belonged to the Ascomycota, 26 to Basidiomycota, 2 to Chytridiomycota, 1 to Zygomycota, 1 to Glomeromycota, and 21 to unknown fungi. The major known orders included Hypocreales and Saccharomycetales. The common fungal genera were Pichia, Fusarium, Alternaria, and Malassezia. Interestingly, most fungi occurring in these Arctic sediments may originate from the terrestrial habitats and different basins in Kongsfjorden (i.e., inner basin, central basin, and outer basin) harbor different sedimentary fungal communities. These results suggest the existence of diverse fungal communities in the Arctic marine sediments, which may serve as a useful community model for further ecological and evolutionary study of fungi in the Arctic.

We assessed the diversity and distribution of fungi in 13 water samples collected from four aquatic environments (stream, pond, melting ice water, and estuary) in the Ny-Ålesund Region, Svalbard (High Arctic) using 454 pyrosequencing with fungi-specific primers targeting the internal transcribed spacer (ITS) region of the ribosomal rRNA gene. Aquatic fungal communities in this region showed high diversity, with a total of 43,061 reads belonging to 641 operational taxonomic units (OTUs) being found. Of these OTUs, 200 belonged to Ascomycota, 196 to Chytridiomycota, 120 to Basidiomycota, 13 to Glomeromycota, and 10 to early diverging fungal lineages (traditional Zygomycota), whereas 102 belonged to unknown fungi. The major orders were Helotiales, Eurotiales, and Pleosporales in Ascomycota; Chytridiales and Rhizophydiales in Chytridiomycota; and Leucosporidiales and Sporidiobolales in Basidiomycota. The common fungal genera Penicillium, Rhodotorula, Epicoccum, Glaciozyma, Holtermanniella, Betamyces, and Phoma were identified. Interestingly, the four aquatic environments in this region harbored different aquatic fungal communities. Salinity, conductivity, and temperature were important factors in determining the aquatic fungal diversity and community composition. The results suggest the presence of diverse fungal communities and a considerable number of potentially novel fungal species in Arctic aquatic environments, which can provide reliable data for studying the ecological and evolutionary responses of fungi to climate change in the Arctic ecosystem.

The actinomycete strain YIM 90462T was isolated from a salt mine sample collected from Yunnan province, south-west China. Comparative 16S rRNA gene sequence analysis demonstrated that the isolate, which had sequence similarities of more than 97 % to Thermobifida alba, Thermobifida fusca and Thermobifida cellulosilytica, was a candidate member of the genus Thermobifida. Subsequently, a polyphasic approach was used to clarify the taxonomic position of strain YIM 90462 T . Its diagnostic diamino acid was meso-diaminopimelic acid and whole-cell sugars contained galactose, xylose and glucose. The predominant menaquinones were MK-10(H 6 ) and MK-10(H 8 ). The major fatty acids were iso-C 16 : 0 and anteiso-C 17 : 0 . Results of DNA-DNA hybridizations and physiological and biochemical tests enabled genotypic and phenotypic differentiation of strain YIM 90462 T from the three Thermobifida species with validly published names. Consequently, it is proposed that strain YIM 90462 T should be recognized as a representative of a novel species of Thermobifida, Thermobifida halotolerans sp. nov. The type strain is YIM 90462 T (5KCTC 19123 T 5DSM 44931 T ). In addition, an emended description of the genus Thermobifida is presented.The establishment of the genus Thermobifida (Zhang et al., 1998) was based on the reclassification of Thermobifida alba and Thermobifida fusca, which were formerly classified as Thermomonospora species (Cross & Goodfellow, 1973;McCarthy & Cross, 1984). Later, Thermobifida cellulosilytica was described by Kukolya et al. (2002). All three Thermobifida species were isolated from manure heaps, composts or damp stored hay and present outstanding cellulose decomposition abilities. T. fusca YX is used as a model organism for studies of aerobic, thermophilic, cellulolytic bacteria and a complete genome is also available for this strain (Wilson, 2004;Lykidis et al., 2007).Strain YIM 90462 T was isolated from a salt mine sample, collected from Yunnan province, south-west China, after 3 weeks incubation at 45 u C on modified ISP medium 4 containing 10 % NaCl (w/v). In view of its thermotolerant and halotolerant capabilities, this strain was studied further and its phylogenetic position was elucidated. Extraction of genomic DNA and amplification of the 16S rRNA gene were done as described by Li et al. (2007). The nearly complete 16S rRNA gene sequence of strain YIM 90462 T was determined and BLAST (Altschul et al., 1997) searches revealed that it possessed significant sequence similarities to those of Thermobifida species. Sequence similarities were determined by using CLUSTAL_X (Thompson et al., 1997