Isolation and Taxonogenomic Analysis of Aliiroseovarius pontivivens sp. nov., a Novel Marine Alphaproteobacterium

Abstract Taxonogenomic analysis was conducted on an alphaproteobacterium, designated as KMU-71T, that was isolated from seawater taken at Dadaepo Harbor in South Korea. Strain KMU-71T was gram-stain-negative, light apricot-colored, rod-shaped, strictly aerobic, and showed no motility. The novel strain could grow at 0–3.0% NaCl concentrations (w/v), pH 5.5–8.5, and 10–37°C. Strain KMU-71T was assigned to the genus Aliiroseovarius based on phylogenetic investigation of the 16S rRNA gene sequences and was closely associated to Aliiroseovarius marinus A6024T, with a sequence similarity of 98.9%. Ubiquinone-10 was the single isoprenoid quinone and C16:0 and C18:1 ω7c were predominant (>10%) fatty acids. The polar lipids were identified as phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine, two unidentified aminolipids, and an unidentified lipid. Strain KMU-71T had a genome size of 3.2 Mb and 59.0% DNA G + C content. The average nucleotide identity value between the genomes of strain KMU-71T and its closely associated taxa were 74.2–88.6%. The digital DNA-DNA hybridization value of novel strain with the strain of A. marinus A6024T was 35.4%. The genome of strain KMU-71T revealed that it contained several genes engaged in the decomposition of biological molecules, indicating a high potential for producing enzymes with practical applications in industry. Hence, the strain represents a novel species of the genus Aliiroseovarius, for which the name Aliiroseovarius pontivivens sp. nov. is proposed. The type strain is KMU-71T (=KCCM 90640T = NBRC 117427T).