Actibacterium atlanticum sp. nov., isolated from surface seawater of the Atlantic Ocean

A taxonomic study was carried out on strain 22II-S11-z10^T, which was isolated from the surface seawater of the Atlantic Ocean. The bacterium was found to be Gram-stain negative, oxidase and catalase positive, oval- to rod-shaped and non-motile. Growth was observed at salinities of 0.5–9 % and at temperatures of 10–41 °C. The isolate can reduce nitrate to nitrite, degrade gelatin and aesculin, but can not degrade Tween 80. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 22II-S11-z10^T belongs to the genus Actibacterium, with the highest sequence similarity to the type strain Actibacterium mucosum CECT 7668^T (97.3 %). The DNA–DNA hybridization estimate value between strain 22II-S11-z10^T and A. mucosum CECT 7668^T was 19.30 ± 2.29 %. The principal fatty acids were identified as Summed Feature 8 (C_18:1 ω7c/ω6c as defined by the MIDI system, 75.2 %) and Summed Feature 3 (C_16:1 ω7c/ω6c, 6.9 %). The G+C content of the chromosomal DNA was determined to be 59.0 mol%. The respiratory quinone was determined to be Q-10 (100 %). Phosphatidylglycerol, phosphatidylcholine, two phospholipids, two aminolipids and two lipids were identified in the polar lipids. The combined genotypic and phenotypic data show that strain 22II-S11-z10^T represents a novel species within the genus Actibacterium, for which the name Actibacterium atlanticum sp. nov. is proposed, with the type strain 22II-S11-z10^T (=MCCC 1A09298^T = LMG 27158^T).