Exiguobacterium mexicanum sp. nov. and Exiguobacterium artemiae sp. nov., isolated from the brine shrimp Artemia franciscana

Two Gram-positive strains isolated from cysts of the brine shrimp Artemia franciscana were subjected to a polyphasic taxonomic analysis. Based on 16S rRNA gene sequence comparison and composition of isoprenoid quinones, peptidoglycan and fatty acids, these organisms are members of the genus Exiguobacterium. Both strains showed 95.9% 16S rRNA gene sequence similarity to one another. The 16S rRNA gene sequences of strain 8NT and 9ANT were 97.5% and 98.9% similar to those of Exiguobacterium aurantiacum DSM 6208T and Exiguobacterium undae DSM 14481T, respectively. Based on differences in chemotaxonomic and physiological characteristics, results of DNA–DNA hybridization and automated riboprinting, two novel species of the genus Exiguobacterium are proposed, Exiguobacterium mexicanum sp. nov. (type strain 8NT=DSM 16483T=CIP 108859T) and Exiguobacterium artemiae sp. nov. (type strain 9ANT=DSM 16484T=CIP 108858T).