Abstract

A grey pink colored bacterium, strain t3-1-3T, was isolated from the air at the foot of the Xiangshan Mountain in Beijing, China. The cells are aerobic, Gram-stain-negative, non-sporeforming, motile and coccoid-rod shaped (0.9–1.2 × 1.9–2.1 μm). Strain t3-1-3T was catalase-positive and oxidase-negative and this strain grew at 4–42°C (optimum 28°C), a pH of 4.0–9.0 (optimum pH 7.0) and under 0–2% (w/v) NaCl (optimum 0–1% NaCl). A phylogenetic analysis based on 16S rRNA gene sequences revealed that strain t3-1-3T was closely related to Azohydromonas riparia UCM-11T (97.4% similarity), followed by Azohydromonas australica G1-2T (96.8%) and Azohydromonas ureilytica UCM-80T (96.7%). The genome of strain t3-1-3T contains 6,895 predicted protein-encoding genes, 8 rRNA genes, 62 tRNA genes and one sRNA gene, as well as five potential biosynthetic gene clusters, including clusters of genes coding for non-ribosomal peptide synthetase (NRPS), bacteriocin and arylpolyene and two clusters of genes for terpene. The predominant cellular fatty acids (> 10.0% of the total) in strain t3-1-3T were summed feature 3 (C16:1ω7c and/or C16:1ω6c, 37.8%), summed feature 8 (C18:1ω7c and/or C18:1ω6c, 29.7%) and C16:0 (17.3%). Strain t3-1-3T contained ubiquinone-8 (Q-8) as the predominant respiratory quinone. The polar lipids of strain t3-1-3T comprised phosphatidyl ethanolamine (PE), phosphatidyl glycerol (PG), diphosphatidyl glycerol (DPG), an unidentified glycolipid (GL), an unidentified aminophospholipid (APL), two unidentified phospholipid (PL1-2) and five unidentified lipid (L1-5). The DNA G + C content of the type strain is 70.3%. The broader range of growth temperature, assimilation of malic acid and trisodium citrate, presence of C18:3ω6c and an unidentified glycolipid and absence of C12:0 2-OH and C16:0iso differentiate strain t3-1-3T from related species. Based on the taxonomic data presented in this study, we suggest that strain t3-1-3T represents a novel species within the genus Azohydromonas, for which the name Azohydromonas aeria sp. nov. is proposed. The type strain of Azohydromonas aeria is t3-1-3T (= CFCC 13393T = LMG 30135T).

• Keywords: Manganese homeostasis;Metal cofactor;Pathogenesis;Salmonella enterica serovar Typhimurium;Transporter proteins