Flavobacterium sandaracinum sp. nov., Flavobacterium caseinilyticum sp. nov., and Flavobacterium hiemivividum sp. nov., novel psychrophilic bacteria isolated from Arctic soil

This study presents taxonomic description of strains LB-D12(T), AT-3-2(T), AT-3-7, and TSA-D2(T) isolated from Arctic soil. All strains were psychrophilic, Gram-stain-negative, aerobic, non-motile, and rod-shaped. Phylogenetic analysis showed that these strains belonged to the genus Flavobacterium. Strains LB-D12(T), AT-3-2(T) and AT-3-7 were closest to Flavobacterium psychrolimnae LMG 22018(T) (98.5-98.8% sequence similarity). Strain TSA-D2(T) was closest to Flavobacterium degerlachei DSM 15718(T) (98.3 % sequence similarity). These strains shared common chemotaxonomic features comprising MK-6 as a sole quinone, phosphatidylethanolamine as the principal polar lipid, and summed feature 3 (iso-C-15(:0) 2-OH and/or C-16:1 omega 7c), iso-C-16(:0) 3-OH, C-15(:1 )omega 6c,( )iso-C-16(: 0), and anteiso-C(15)(:0 )as the main fatty acids. The ANI and dDDH values between these novel isolates and their closest relatives were below the cut-off values of 95 and 70 %, respectively used for species demarcation. The DNA G+C content of all strains ranged from 34.2 to 34.6 mol%. The obtained polyphasic taxonomic data suggested that the isolated strains represent novel species within the genus Flavobacterium, for which the names Flavobacterium sandaracinum sp. nov. (type strain LB-D12(T)=KEMB 9005-737(T)=KACC 21180(T)=NBRC 113784(T)), Flavobacterium caseinilyticum sp. nov. (type strain AT-3-2T=KEMB 9005-738(T)=KACC 21176(T)=NBRC 113785(T)), and Flavobacterium hiemivividum sp. nov. (type strain TSA-D2(T)=KEMB 9005-741(T)=KACC 21179(T)=NBRC 113788(T)) are proposed.