Aquimarina atlantica sp. nov., isolated from surface seawater of the Atlantic Ocean.

Abstract

A taxonomic study was carried out on strain 22II-S11-z7(T), which was isolated from the surface seawater of the Atlantic Ocean. The bacterium was found to be Gram-negative, oxidase negative and catalase positive, long-rod shaped, and gliding. Growth was observed at salinities of 1-5% and at temperatures of 10-41°C. The isolate was capable of hydrolysing gelatin and Tween 80 and able to reduce nitrate to nitrite, but unable to degrade aesculin. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 22II-S11-z7(T) belongs to the genus Aquimarina, with highest sequence similarity to Aquimarina megaterium XH134(T) (98.31%), followed by Aquimarina macrocephali JAMB N27(T) (96.59%); other species of the genus Aquimarina shared 93.63-96.08% sequence similarity. The ANI value between strain 22II-S11-z7(T) and A. megaterium XH134(T) was found to be 91.86-91.81%. The DNA-DNA hybridization estimated value between strain 22II-S11-z7(T) and A. megaterium XH134(T) was 47.7±2.6%. The principal fatty acids were identified as Summed Feature 3 (C16:1 ω7c/ω6c, as defined by the MIDI system; 8.1%), SummedFeature 9 (iso-C17:1 ω7c/C16:110-methyl; 6.8%), iso-C15:0 G (11.3%), iso-C15:0 (24.9%), iso-C16:0 (5.7%), C16:0 (5.2%), iso-C15:0 3OH (6.4%) and iso-C17:0 3OH (21.5%). The G+C content of the chromosomal DNA was determined to be 32.99mol%. The respiratory quinone was determined to be MK-6 (100%). Phosphatidylethanolamine, two unidentified aminolipids, five unidentified phospholipids and two unidentified lipids were found to be present. The combined genotypic and phenotypic data show that strain 22II-S11-z7(T) represents a novel species within the genus Aquimarina, for which the name Aquimarina atlantica sp. nov. is proposed, with the type strain 22II-S11-z7(T) (=MCCC 1A09239(T)=KCTC 42003(T)).