Red-pink pigmented Hymenobacter coccineus sp. nov., Hymenobacter lapidarius sp. nov. and Hymenobacter glacialis sp. nov., isolated from rocks in Antarctica

Abstract

Four rod-shaped and Gram-stain-negative bacterial strains, CCM 8647, CCM 8649T, CCM 8643T and CCM 8648T, were isolated from rock samples collected on James Ross Island, Antarctica. Extensive biotyping, fatty acid profiling, chemotaxonomy, 16S rRNA gene sequencing and whole-genome sequencing was applied to isolates to clarify their taxonomic position. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that all four isolates belonged to the genus Hymenobacter. Strains CCM 8649T and CCM 8647 were most closely related to Hymenobacter arizonensis OR362-8T (94.4 % 16S rRNA gene sequence similarity), strain CCM 8643T to Hymenobacter terrae DG7AT (96.3 %) and strain CCM 8648T to Hymenobacter glaciei VUG-A130T (96.3 %). The predominant fatty acids of CCM 8649T and CCM 8647 were summed feature 3 (C16 : 1ω7c/C16 : 1ω6c), C16 : 1ω5c and iso-C15 : 0, whereas those of CCM 8643T and CCM 8648T were summed feature 3 (C16 : 1ω7c/C16 : 1ω6c) and C16 : 1ω5c. The quinone systems contained exclusively menaquinone MK-7. The major polyamine was sym-homospermidine. All four strains contained the major polar lipid phosphatidylethanolamine. The G+C content of genomic DNA ranged from 60-63 mol%. Whole-genome sequencing data supported the finding that isolates represented distinct species of the genus Hymenobacter. On the basis of the results obtained, three novel species are proposed for which the names Hymenobacter coccineus sp. nov., Hymenobacter lapidarius sp. nov. and Hymenobacter glacialis sp. nov. are suggested, with the type strains CCM 8649T (=LMG 29441T=P5239T), CCM 8643T (=LMG 29435T=P3150T) and CCM 8648T (=LMG 29440T=P5086T), respectively.

Hymenobacter caeli sp. nov., an airborne bacterium isolated from King George Island, Antarctica

“… †Data from Hirsch et al [1]. ‡Data from Sedláček et al [7]. §Different results were reported in the original description [7].…”

Hymenobacter artigasi sp. nov., isolated from air sampling in maritime Antarctica

“…Species of this genus have recently been isolated from many cold environments, e.g. sediment in the permafrost [5, 7], Antarctic rocks [8], Antarctic soils [1, 9] and snow [10, 11]. At the time of writing, there were 82 species of the genus Hymenobacter recorded on the LPSN (https://lpsn.dsmz.de/genus/hymenobacter, accessed March 2020).…”

Hymenobacter terrestris sp. nov. and Hymenobacter lapidiphilus sp. nov., isolated from regoliths in Antarctica

“…Over the last few years many novel hymenobacters have been discovered from different sources including cold environments, such as a glacial till [3], glacier ice core [4, 5], karst cave soils [6, 7], permafrost in mountains [8, 9], marine sediment in the Arctic [10] and deep-sea water [11]. A few novel hymenobacters have recently been found in Antarctica as well, such as Hymenobacter nivis discovered from red snow [12], Hymenobacter coccineus , Hymenobacter lapidarius and Hymenobacter glacialis from rocks [13], Hymenobacter rubripertinctus from Antarctic tundra soil [14], Hymenobacter amundsenii from regoliths [15], and Hymenobacter humicola from Antarctic soils [16]. The genus Hymenobacter is a member of the family Hymenobacteraceae in the phylum Bacteroidetes.…”

“…Anaerobic growth on R2A agar was tested in an anaerobic jar at 15 °C for 72 h using Anaerocult A (Merck) and compared to those cultivated in the ambient atmosphere. Growth at different temperatures (1, 5, 10, 15, 20, 25 and 30 °C) and tolerance to various NaCl concentrations (0.5, 1, 2 and 3%, w/v) were determined based on cultivation on R2A agar plates for up to 4 days [13]. The pH range for growth was tested on R2A agar plates adjusted to pH 6.0–9.0 using different buffer systems (pH 6.0–8.0, 0.1 M KH 2 PO 4 /0.1 M NaOH; pH 9.0, 0.1 M NaHCO 3 /0.1 M Na 2 CO 3 ; at intervals of 1 pH unit) for 1 week at 15 °C [40].…”