Aequorivita flava sp. nov., isolated from deep-sea sediments.

ABSTRACT

Three Gram-stain-negative, aerobic, non-motile, chemoheterotrophic, short-rod-shaped bacteria, designated CDY1-MB1T, CDY2-MB3, and BDY3-MB2, were isolated from three marine sediment samples collected in the eastern Pacific Ocean. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these strains were related to the genus Aequorivita and close to the type strain of Aequorivita vitellina F4716T (with similarities of 98.0-98.1%). Strain CDY1-MB1T can grow at 15-37 °C (optimum 30 °C) and in media with pH 6-9 (optimum, pH 7), and tolerate up to 10% (w/v) NaCl. The predominant cellular fatty acids of strain CDY1-MB1T were iso-C15  0 (20.7%) and iso-C17  0 3-OH (12.8%); the sole respiratory quinone was menaquinone 6; the major polar lipids were phosphatidylethanolamine, two unidentified aminolipids and two unidentified polar lipids. The digital DNA-DNA hybridization/average nucleotide identity values between strains CDY1-MB1T, CDY2-MB3, and BDY3-MB2 and A. vitellina F4716T were 24.7%/81.6-81.7%, thereby indicating that strain CDY1-MB1T should represent a novel species of the genus Aequorivita. The genomic DNA G+C contents were 37.6 % in all three strains. Genomic analysis showed the presence of genes related to nitrogen and sulphur cycling, as well as metal reduction. The genetic traits of these strains indicate their possible roles in nutrient cycling and detoxification processes, potentially shaping the deep-sea ecosystem's health and resilience. Based upon the consensus of phenotypic and genotypic analyses, strain CDY1-MB1T should be classified as a novel species of the genus Aequorivita, for which the name Aequorivita flava sp. nov. is proposed. The type strain is CDY1-MB1T (=MCCC 1A16935T=KCTC 102223T).