Ten novel psychrophilic Flavobacterium species from Tibetan Plateau glaciers define a cryospheric lineage with global cold-origin relatives
Year: 2026
Type: article
Abstract: Twenty-three novel psychrophilic bacteria, represented by the type strains LB2P44 T , LB2P6 T , LB1P62 T , LB3P6 T , LS1P3 T , XS2P39 T , XS1P32 T , ZB4P13 T , ZS1P14 T and GT2P42 T , were isolated from ice, cryoconite and meltwater of five Tibetan Plateau glaciers. All strains were Gram-stain-negative, aerobic, rod-shaped and psychrophilic, with optimal growth at 14–20 °C and pH 7.0. 16S rRNA gene sequence similarities to validly named Flavobacterium species ranged from 98.12% to 99.56%. Phylogenomic analysis of 81 concatenated core genes positioned the 23 strains (comprising the ten novel species) within a robust monophyletic clade — the ‘Cryospheric Lineage’ — together with 31 other psychrophilic type strains predominantly from glaciers, permafrost and polar regions. Average nucleotide identity (ANI) values of ≤94.4% and digital DNA–DNA hybridization (dDDH) values of ≤57.3% against closest relatives were below species thresholds (95–96% ANI, 70% dDDH). Major fatty acids were iso-C 15:0 (8.1–16.8%), iso-C 15:0 3-OH (3-hydroxy, 5.2–16.0%) and summed feature 3 (C 16:1 ω 7 c and/or C 16:1 ω 6 c , 10.1–27.6%), with elevated branched-chain and unsaturated components typical of cold adaptation. Polyphasic taxonomic evidence supports the description of ten novel species within the genus Flavobacterium: Flavobacterium amylolyticum sp. nov. (LB2P44 T =CGMCC 1.11256 T =NBRC 114815 T ), Flavobacterium glucosi sp. nov. (LB2P6 T =CGMCC 1.11263 T =NBRC 114816 T ), Flavobacterium esculini sp. nov. (LB1P62 T =CGMCC 1.11346 T =NBRC 114817 T ), Flavobacterium labens sp. nov. (LB3P6 T =CGMCC 1.11428 T =NBRC 114818 T ), Flavobacterium pasteuri sp. nov. (LS1P3 T =CGMCC 1.11474 T =NBRC 114821 T ), Flavobacterium rhamnosi sp. nov. (XS2P39 T =CGMCC 1.23204 T =NBRC 115054 T ), Flavobacterium frigidum sp. nov. (XS1P32 T =CGMCC 1.23370 T =NBRC 115055 T ), Flavobacterium glycogeni sp. nov. (ZB4P13 T =CGMCC 1.24050 T =NBRC 115056 T ), Flavobacterium kochi sp. nov. (ZS1P14 T =CGMCC 1.24093 T =NBRC 114828 T ) and Flavobacterium cryophilum sp. nov. (GT2P42 T =CGMCC 1.24821 T =NBRC 114831 T ).
Authors: Qing Liu, Lei-Lei Yang, Yu-Hua Xin
Institutions: Chinese Academy of Sciences, Institute of Microbiology
Language: English
Topic: Polar Research and Ecology
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: hybrid
Award: G132271440
OpenAlex ID: W7123517122