Halomonas Icarae Sp. Nov., A Moderately Halophilic Bacterium Isolated From Beach Soil In India

A moderately halophilic, Gram-stain-negative, aerobic bacterium, strain D1-1(T), belonging to the genus Halomonas, was isolated from soil sampled at Pentha beach, Odisha, India. Phylogenetic trees reconstructed based on 16S rRNA genes and multilocus sequence analysis of gyrB and rpoD genes revealed that strain D1-1(T) belonged to the genus Halomonas and was most closely related to Halomonas alimentaria YKJ-16(T) (98.1%) followed by Halomonas ventosae Al12(T) (97.5 %), Halomonas sediminicola CPS11(T) (97.5%), Halomonas fontilapidosi 5CR(T) (97.4%) and Halomonas halodenitrificans DSM 735(T) (97.2%) on the basis of 16S rRNA gene sequence similarity. Sequence identities with other species within the genus were lower than 97.0 %. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values of 22.4-30 % and 79.5-85.4% with close relatives of H. halodenitrificans DSM 735(T), H. alimentaria YKJ-16(T), H. ventosae Al12(T) and H. fontilapidosi 5CR(T) were lower than the threshold recommended for species delineation (70% and 95-96% for dDDH and ANI, respectively). Further, strain D1-1(T) formed yellow-coloured colonies; cells were rod-shaped, motile with optimum growth at 30 degrees C (range, 4-45 degrees C) and 2-8% NaCl (w/v; grew up to 24% NaCl). The major fatty acids were summed feature 8 (C-18:1 omega 7c/C-18:1 omega 6c), summed feature 3 (C-16:1 omega 7c/C-16:1 omega 6c) and C-16:0 and the main respiratory quinone was ubiquinone Q-9 in line with description of the genus. Based on its chemotaxonomic and phylogenetic characteristics and genome uniqueness, strain D1-1(T) represents a novel species in the genus Halomonas, for which we propose the name Halomonas icarae sp. nov., within the family Halomonadaceae. The type strain is D1-1(T) (=JCM 33602(T)=KACC 21317(T)=NAIMCC-B-2254(T)).