During the study of bacteria associated with bats affected by white-nose syndrome hibernating in caves in the Czech Republic, we isolated two facultatively anaerobic, Gram-stain-negative bacteria, designated strains 12T and 52T. Strains 12T and 52T were motile, rod-like bacteria (0.5–0.6 µm in diameter; 1–1.3 µm long), with optimal growth at 20–35 °C and pH 6–8. On the basis of the almost complete sequence of their 16S rRNA genes they should be classified within the genus Serratia ; the closest relatives to strains 12T and 52T were Serratia quinivorans DSM 4597T (99.5 % similarity in 16S rRNA gene sequences) and Serratia ficaria DSM 4569T (99.5 % similarity in 16S rRNA gene sequences), respectively. DNA–DNA relatedness between strain 12T and S. quinivorans DSM 4597T was only 37.1 % and between strain 52T and S. ficaria DSM 4569T was only 56.2 %. Both values are far below the 70 % threshold value for species delineation. In view of these data, we propose the inclusion of the two isolates in the genus Serratia as representatives of Serratia myotis sp. nov. (type strain 12T = CECT 8594T = DSM 28726T) and Serratia vespertilionis sp. nov. (type strain 52T = CECT 8595T = DSM 28727T).
The genus Leptolyngbya Anagnostidis & Komárek (1988) was described from a set of strains identified as ‘LPP-group B’. The morphology within this group is not particularly informative and underestimates the group’s genetic diversity. In the present study, two new pseudanabaenacean genera related to Leptolyngbya morphotypes, Pantanalinema gen. nov. and Alkalinema gen. nov., are described under the provisions of the International Code of Nomenclature for Algae, Fungi and Plants, based on a polyphasic approach. Pantanalinema gen. nov. (type species Pantanalinema rosaneae sp. nov.) has sheaths and trichomes with slight gliding motility, which distinguish this genus from Alkalinema gen. nov. (type species Alkalinema pantanalense sp. nov.), which possesses trichomes arranged in an ornate (interwoven) pattern. 16S rRNA gene sequences of strains of Pantanalinema and Alkalinema exhibited low identity to each other (≤91.6 %) and to other sequences from known pseudanabaenacean genera (≤94.3 and 93.7 %, respectively). In a phylogenetic reconstruction, six sequences from strains of Pantanalinema and four from strains of Alkalinema formed two separate and robust clades (99 % bootstrap value), with the genera Oculatella and Phormidesmis, respectively, as the closest related groups. 16S–23S rRNA intergenic spacer sequences and secondary structures of strains of Pantanalinema and Alkalinema did not correspond to any previous descriptions. The strains of Pantanalinema and Alkalinema were able to survive and produce biomass at a range of pH (pH 4–11) and were also able to alter the culture medium to pH values ranging from pH 8.4 to 9.9. These data indicate that cyanobacterial communities in underexplored environments, such as the Pantanal wetlands, are promising sources of novel taxa.