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

Abstract

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}ω7c), iso-C_{16 : 0} 3-OH, C_{15 : 1}ω6c, 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-3-2^T=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.

Keywords: Arctic soil; Bacteroidetes; Flavobacterium; novel species; psychrophilic.