Marinitoga aeolica sp. nov., a novel thermophilic anaerobic heterotroph isolated from a shallow hydrothermal field of Panarea Island in the Aeolian archipelago, Italy

A novel thermophilic strain, designated BP5-C20A^T, was isolated from the shallow hydrothermal field of the Panarea island in the Aeolian archipelago close to Sicily, Italy. Cells are motile rods surrounded with a ‘toga’, Gram-stain-negative and display a straight to curved morphology during the exponential phase. Strain BP5-C20A^T is thermophilic (optimum 55 °C), moderately acidophilic (optimum pH 5.6) and halotolerant (optimum 25 g l⁻¹ NaCl). It can use yeast extract, peptone and tryptone. It uses the following carbohydrates: cellobiose, fructose, glucose, maltose, starch, sucrose and xylan. Elemental sulphur is used as an electron acceptor and reduced to hydrogen sulphide. The predominant cellular fatty acid is C_{16: 0}. Phylogenetic analysis showed that strain BP5-C20A^T shared 97.3 % 16S rRNA gene sequence identity with the closest related species Marinitoga lauensis LG1^T. The complete genome of strain BP5-C20A^T is 2.44 Mb in size with a G+C content of 27.3 mol%. The dDDH and ANI values between the genomes of strains BP5-C20A^T and M. lauensis LG1^T are 31.0 and 85.70% respectively. Finally, from its physiologi-cal, metabolic and genomic characteristics, strain BP5-C20A^T (=DSM 112332^T=JCM 39183^T) is proposed as representative of a novel species of the genus Marinitoga named Marinitoga aeolica sp. nov. and belonging to the order Petrotogales, in the phylum Thermotogota.