Find in Library

A group of seven bacterial strains producing blue-purple pigmented colonies on R2A agar was isolated from freshwater samples collected in a deglaciated part of James Ross Island and Eagle Island, Antarctica, from 2017–2019. The isolates were psychrophilic, oligotrophic, resistant to chloramphenicol, and exhibited strong hydrolytic activities. To clarify the taxonomic position of these isolates, a polyphasic taxonomic approach was applied based on sequencing of the 16S rRNA, <i>gyr</i>B and <i>lep</i>A genes, whole-genome sequencing, rep-PCR, MALDI-TOF MS, chemotaxonomy analyses and biotyping. Phylogenetic analysis of the 16S rRNA gene sequences revealed that the entire group are representatives of the genus <i>Massilia</i>. The closest relatives of the reference strain P8398^T were <i>Massilia atriviolacea</i>, <i>Massilia violaceinigra</i>, <i>Massilia rubra</i>, <i>Massilia mucilaginosa</i>, <i>Massilia aquatica</i>, <i>Massilia frigida</i>, <i>Massilia glaciei</i> and <i>Massilia eurypsychrophila</i> with a pairwise similarity of 98.6–100% in the 16S rRNA. The subsequent <i>gyr</i>B and <i>lep</i>A sequencing results showed the novelty of the analysed group, and the average nucleotide identity and digital DNA–DNA hybridisation values clearly proved that P8398^T represents a distinct <i>Massilia</i> species. After all these results, we nominate a new species with the proposed name <i>Massilia antarctica</i> sp. nov. The type strain is P8398^T (= CCM 8941^T = LMG 32108^T).