Exiguobacterium aquaticum sp. nov., a member of the genus Exiguobacterium.

Research paper by Revti R Raichand, Siddhika S Pareek, Nitin Kumar NK Singh, Shanmugam S Mayilraj

Indexed on: 08 Nov '11Published on: 08 Nov '11Published in: International journal of systematic and evolutionary microbiology


A Gram-positive, motile, short rod-shaped, orange pigmented bacterium, designated strain IMTB-3094(T), was isolated from a water sample collected from Tikkar Tal Lake, Haryana, and subjected to detailed polyphasic taxonomic analysis. Strain IMTB-3094(T) possessed most of the phenotypic and chemotaxonomic properties of the genus Exiguobacterium and, based on 16S rRNA gene sequence analysis, was assigned to this genus. Strain IMTB-3094(T) exhibited the highest 16S rRNA gene sequence similarity to Exiguobacterium mexicanum MTCC 7759(T) (99.5 %) followed by Exiguobacterium aurantiacum MTCC 6414(T) (99.1 %), Exiguobacterium aestuarii MTCC 7750(T) (98.0 %), Exiguobacterium profundum MTCC 10851(T) (98.0 %) and Exiguobacterium marinum MTCC 7751(T) (98.0 %). The G+C content of the genomic DNA of strain IMTB-3094(T) was 53.2 mol% and a DNA-DNA relatedness study confirmed that it represents a novel species. The major fatty acids of strain IMTB-3094(T) were iso-C(17 : 0) (16.1 %), anteiso-C(13 : 0) (19.0 %), iso-C(13 : 0) (11.9 %), iso-C(15 : 0) (9.8 %) and iso-C(17 : 1) (12.7 %). The predominant quinones were MK-7 (55.0 %) and MK-6 (26.0 %) with minor amounts of MK-8 (12.0 %). Based on phenotypic, chemotaxonomic and phylogenetic analyses, strain IMTB-3094(T) represents a novel species of the genus Exiguobacterium, for which the name Exiguobacterium aquaticum sp. nov. is proposed. The type strain is IMTB-3094(T) (= MTCC 10958(T) = JCM 17977(T)).