Pseudopontixanthobacter vadosimaris gen. nov., sp. nov., isolated from shallow sea near Kueishan Island

Abstract

A Gram-stain-negative and aerobic bacterial strain, designated as JL3514T, was isolated from surface water of the hydrothermal system around Kueishan Island. The isolate formed red colonies and cells were non-flagellated, rod-shaped and contained methanol-soluble pigments. Growth was observed at 10–50 °C (optimum, 30 °C), at pH 5.0–9.0 (optimum, pH 7.0) and in the presence of 0–9 % (w/v) NaCl (optimum, 2 %). Strain JL3514T was positive for catalase and weakly positive for oxidase. Results of 16S rRNA gene sequence analyses showed highest similarities to species in the family Erythrobacteraceae , namely Croceibacterium atlanticum (96.1 %), Pelagerythrobacter marensis (96.0 %), Tsuneonella rigui (96.0 %) and Altericroceibacterium xinjiangense (96.0 %). Phylogenetic analysis based on core gene sequences revealed that the isolate formed a distinct branch with the related species and it had a lower average amino acid identity value than the suggested threshold for genera boundaries. The major fatty acids (>5 %) were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C16 : 0, C17 : 1 ω6c, C14 : 0 2-OH and C12 : 0. The dominant polar lipids comprised diphosphatidylglycerol, sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, glycolipid, two unidentified lipids and one unidentified phospholipid. The main respiratory quinones were ubiquinone-10 (95.7 %) and ubiquinone-9 (4.3 %). The DNA G+C content from the genome was 63.0 mol%. Based on the presented data, we consider strain JL3514T to represent a novel genus of the family Erythrobacteraceae , with the name Pseudopontixanthobacter vadosimaris gen. nov., sp. nov. The type strain is JL3514T (=KCTC 62623T=MCCC 1K03561T).

Phylotaxonomic assessment based on four core gene sets and proposal of a genus definition among the families Paracoccaceae and Roseobacteraceae

“…Recently, thresholds for genus boundaries of the family Erythrobacteraceae were proposed as 70 % and 0.4 for AAI and ED based on 288 single-copy orthologous clusters, respectively [61]. This established a reasonable taxonomy of the family Erythrobacteraceae , and the genus definition was well accepted and used in subsequent genus proposals [62, 63].…”

Actirhodobacter atriluteus gen. nov., sp. nov., isolated from the surface water of the Yellow Sea

“…and Tsuneonella (Tsu. ), according to the genus boundaries of average amino acid identity (AAI, 70%) and evolutionary distance (0.40) recently proposed for the family Erythrobacteraceae (Xu et al 2020;Sun et al 2020). Bacteria of the family Erythrobacteraceae were isolated from various habitats, including air (Xue et al 2016), soil , sediment (Park et al 2019b), tidal at (Park et al 2019a), seawater (Li et al 2017a; Meng et al 2019), estuary (Park et al 2019c), freshwater (Kang et al 2016).…”