Aliifodinibius halophilus sp. nov., a moderately halophilic member of the genus Aliifodinibius, and proposal of Balneolaceae fam. nov.

Abstract

A novel Gram-stain-negative, rod-shaped, facultatively anaerobic, oxidase-negative and catalase-positive bacterium, designated 2W32T, was isolated from a marine solar saltern on the coast of Weihai, Shandong Province, China. Strain 2W32T was tolerant to moderate salt conditions. Optimal growth occurred at 33-37 °C (range 20-45 °C) and pH 7.5-8.0 (range pH 7.0-8.5) with 6-10 % (w/v) NaCl (range 2-18 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 2W32T shared highest similarity with Aliifodinibius sediminis YIM J21T (94.6 %), Aliifodinibius roseus YIM D15T (94.4 %), Fodinibius salinus YIM C003T (93.6 %), Gracilimonas tropica CL-CB462T (88.6 %) and Balneola vulgaris 13IX/A01/164T (86.4 %) and less than 83.0 % similarity with other species of the phylum Bacteroidetes. The isolate and closely related species formed a novel family-level clade in the phylum Bacteroidetes. The polar lipid profile of the novel isolate consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an unidentified aminolipid, an unidentified glycolipid and an unidentified lipid. The dominant cellular fatty acids (>10 %) were iso-C15 : 0, iso-C17 : 1ω9c and summed feature 3 (C16:1ω7c and/or iso-C15 : 0 2-OH) and the sole respiratory quinone was menaquinone 7 (MK-7). The DNA G+C content of strain 2W32T was 47.5 mol %. Comparative analysis of 16S rRNA gene sequences and characterization indicated that strain 2W32T represents a novel species within the genus Aliifodinibius, for which the name Aliifodinibius halophilus sp. nov. is proposed. The type strain is 2W32T (=KCTC 42497T=CICC 23869T). In addition, a novel family, Balneolaceae fam. nov., is proposed to accommodate the genera Fodinibius, Aliifodinibius, Gracilimonas and Balneola.