Janthinobacterium violaceinigrum sp. nov., Janthinobacterium aquaticum sp. nov. and Janthinobacterium rivuli sp. nov., isolated from a subtropical stream in China

Abstract

Four strains assigned the names FT13W^T, FT14W, FT58W^T and FT68W^T were isolated from a subtropical stream in PR China. All the strains were Gram-stain-negative, catalase- and oxidase-positive, rod-shaped and motile with flagella. Comparisons based on 16S rRNA gene sequences showed that strains FT13W^T, FT14W, FT58W^T and FT68W^T belonged to genus Janthinobacterium and shared 16S rRNA gene similarities in the range of 98.8-99.7 % with Janthinobacterium lividum DSM 1522^T, Janthinobacterium agaricidamnosum DSM 9628^T and 'Janthinobacterium svalbardensis JA-1', respectively. The calculated pairwise average nucleotide identity (ANI) values among the genomes of above seven strains were in the range of 79.0-92.2 %, except that the ANI value was 96.8 % between strain FT13W^T and FT14W. The respiratory quinone of strains FT13W^T, FT14W, FT58W^T and FT68W^T was determined to be Q-8. The major fatty acids were C_{16 : 1} ω7c, C_{16 : 0}, C_{18 : 1} ω7c and C_{12 : 0}. The polar lipids included phosphatidylethanolamine, phosphatidylglycerol and one unidentified phospholipid. The genome sizes of strains FT13W^T, FT14W, FT58W^T and FT68W^T were 6.45, 6.38, 5.73 and 6.37 Mbp with G+C contents of 63.4, 63.7, 61.6 and 63.1 mol%, respectively. Combining phenotypic, biochemical, genotypic and ANI data, strain FT13W^T and FT14W should belong to the same species. The four strains were considered to represent three novel species within genus Janthinobacterium, for which the names Janthinobacterium violaceinigrum sp. nov. (type strain FT13W^T=GDMCC 1.1638^T=KACC 21319^T), Janthinobacterium aquaticum sp. nov. (FT58W^T=GDMCC 1.1676^T=KACC 21468^T) and Janthinobacterium rivuli sp. nov. (FT68W^T=GDMCC 1.1677^T=KACC 21469^T) are proposed.

Keywords: Janthinobacterium; polyphasic taxonomy; subtropical stream.