Carnobacterium iners sp. nov., a psychrophilic, lactic acid-producing bacterium from the littoral zone of the Forlidas pond (Pensacola mountains), Antarctica

Two rod-shaped, lactic acid-producing, Gram-positive bacteria were isolated from a microbial mat actively growing in the littoral zone of an Antarctic lake (Forlidas Pond) in the Pensacola mountains. A polyphasic taxonomic study was conducted involving phylogenetic analysis of the 16S rRNA genes and multi-locus sequence analysis of the pheS, rpoA, and atpA genes. The obtained results proved that one strain, designated LMG 26641, belongs to Carnobacterium alterfunditum and that the other strain, designated LMG 26642T, can be assigned to a novel species with Carnobacterium funditum as its closest phylogenetic neighbor (99.2% 16S rRNA gene sequence similarity towards the type strain). DNA-DNA hybridization experiments confirmed that the latter strain represents a novel species, for which we propose the name Carnobacterium iners sp. nov., with strain LMG 26642T (= CCUG 62000T) as the type strain. Carnobacterium iners sp. nov. can be distinguished biochemically from other Carnobacterium species by the lack of acid production from carbohydrates.