A novel Pseudarthrobacter species isolated from an ulcer of a farmed atlantic salmon (Salmonis alba)

A Gram-stain positive, pleomorphic, oxidase-negative, non-motile isolate from the ulcer of a farmed atlantic salmon (Salmonis alba), designated strain T11bT, was subjected to a comprehensive taxonomic investigation. A comparative analysis of the 16S rRNA gene sequence showed highest similarities to Pseudarthrobacter siccitolerans and Pseudarthrobacter defluvii (98.0-98.1 %). The quinone system consisted of major amounts of MK-8(H2), minor amounts of MK-9(H2) and traces of MK-8 and MK-9. The polar lipid profile of strain T11bT contained phosphatidylinositol (PI) and phosphatidylinositol-mannoside (PIM) as major lipids and phosphatidylglycerol (PG) and an acidic glycolipid (aGL) in moderate amounts. In addition small amounts of diphosphatidylglycerol (DPG), a phosholipid (PL), an aminolipid (AL1) and two lipids of unknown group affiliation (L1 and L2) were found. The polyamine pattern was composed of the major components spermidine and spermine. 1,3-diaminopropane, putrescine, cadaverine, sym-homospermidine, and tyramine were found in minor or trace amounts. The diaminoacid of the peptidoglycan was meso-diaminopimelic acid. In the fatty acid profile straight chain, anteiso and iso branched fatty acids predominated (C15:0 anteiso, C16:0 iso, C17:0 anteiso). Corynemycolic acids were not detected. Physiological traits as well as unique traits in the polar lipid profile and the fatty acid pattern distinguished strain T11bT from the next related species. All these data point to the fact, that strain T11bT is representing a novel species of the genus Pseudarthrobacter