Description of Flavobacterium cyclinae sp. nov. and Flavobacterium channae sp. nov., isolated from the intestines of Cyclina sinensis (Corb shell) and Channa argus (Northern snakehead)

Abstract

Two novel bacterial strains, KSM-R2A25^T and KSM-R2A30^T, were isolated from intestines of Cyclina sinensis (corb shell) and Channa argus (northern snakehead), respectively. Both specimens were collected in Korea. The strains were Gramstain-negative, non-motile, and strictly aerobic. According to phylogenetic analyses based on 16S rRNA gene sequences, strains belonged to the genus Flavobacterium within the family Flavobacteriaceae. 16S rRNA gene sequences of strains KSM-R2A25^T and KSM-R2A30^T were closely related to Flavobacterium cucumis DSM 18830^T and Flavobacterium aquaticum JC164^T with sequence similarities of 97.77% and 98.54%, respectively. Further genomic analyses including reconstruction of the UBCG tree and overall genome-related indices suggested them as novel species of the genus Flavobacterium. Both strains contained menaquinone with six isoprene units (MK-6) as a major isoprenoid quinone and iso-C_15:1 G, iso-C_15:0 and iso-C_16:0 as major cellular fatty acids. The major polar lipid in both strains was phosphatidylethanolamine. The genomic G + C contents of strains KSM-R2A25^T and KSM-R2A30^T were 31.7 and 31.9%, respectively. Based on the polyphasic taxonomic study presented here, strains KSM-R2A25^T and KSM-R2A30^T represent novel species of the genus Flavobacterium, for which the names Flavobacterium cyclinae sp. nov and Flavobacterium channae sp. nov are proposed. The type strains of F. cyclinae sp. nov and F. channae sp. nov are KSM-R2A25^T (= KCTC 82978^T = JCM 34997^T) and KSM-R2A30^T (= KCTC 82979^T = JCM 34998^T), respectively.

Keywords: Channa argus; Cyclina sinensis; Flavobacterium; Flavobacterium channae; Flavobacterium cyclinae; gut microbiota; taxonomy.