Janthinobacterium kumbetense sp. nov., a violacein producing bacterium isolated from spring water in Turkey, and investigation of antimicrobial activity of violacein


 Strain GKT was isolated from the Kumbet plateu of Giresun in Turkey. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain GKT belonged to genus Janthinobacterium and 16S rRNA gene sequence similarities with all type strains of the genus Janthinobacterium were 98.89–99.78%. The calculated pairwise average nucleotide identity (ANI) values between strain GKT and all type strains of Janthinobacterium species were in the range of 79.8–93.2%. In addition, digital DNA–DNA hybridization (dDDH) values were in the range of 23.0–51.7%. Major fatty acids are C10:03OH, C12:0, C16:1ω7c, C16:0, C18:1ω7c and polar lipids included phosphatidylethanolamine, phosphatidylglycerol, also one unidentified phospholipid and one unidentified aminophospholipid. The respiratory quinone of strain GKT was determinated to be Q-8. The genome sizes of strain GKT was 6 197 538 bp with 63.16% G + C ratio. Strain GKT is gram-stain-negative, aerobic, rod-shaped and motile. A violet pigment was produced by strain GKT. The crude violacein pigments were separated into three diferent bands on a TLC sheet. Then violacein and deoxyviolacein were purifed by vacuum liquid column chromatography and identifed by NMR spectroscopy. The antimicrobial activities of purifed violacein and deoxyviolacein were screened for seven microorganisms. Based on the results of the morphological, biochemical, physiological, phylogenetic and genomic characteristics, we propose classifying the strain GKT as representative of a novel species of the genus Janthinobacterium, for which the name Janthinobacterium kumbetense sp. nov. is proposed (GKT = LMG 32662T = DSM 11423T).