Pseudaquidulcibacter saccharophilus gen. nov., sp. nov., a novel member of family Caulobacteraceae, isolated from a water purification facility with supplement of starch as a carbon source.

During a survey of microbial communities in the influent (ambient water) and effluent of a water purification facility with aeration and supplement of starch as carbon source, a novel bacterial strain, designated SZ9T, was isolated from the effluent sample. Colonies of strain SZ9T were small (approximately 0.5-1.0 mm in diameter), creamy-white, circular, smooth, translucent and convex. Cells were facultative anaerobic, motile by means of a single polar flagellum, rod-shaped, multiplied by binary fission, Gram-stain-negative, oxidase-positive and catalase-negative. Growth occurred at 10-40 °C (optimum, 28 °C) and pH 5.5-8.0 (optimum, pH 7.5). The range of NaCl concentration for growth was 0-1.0 % (w/v), with an optimum of 0-0.5 % (w/v). Phylogenetic analysis based on 16S rRNA gene sequences suggested that strain SZ9T formed a lineage within the family Caulobacteraceae of the class Alphaproteobacteria and showed the highest 16S rRNA gene sequence similarities to Aquidulcibacter paucihalophilus TH1-2T (92.44%), followed by Vitreimonas flagellata SYSU XM001T (89.61 %), Asprobacter aquaticus DRW22-8T (89.49 %) and Hyphobacterium vulgare WM6T (89.49%). The predominant fatty acids (>10 % of the total fatty acids) of strain SZ9T was summed feature 3 (comprising C16 : 1 ω6c and/or C16 : 1 ω7c), summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c) and C16 : 0. The sole respiratory quinone was ubiquinone-10, and the major polar lipids were phosphatidylcholine and two unidentified glycolipids. The whole genome of strain SZ9T was 2 842 140 bp in size, including 2769 protein-coding genes, 37 tRNA genes and two rRNA genes, and the genomic G+C content was 41.4 mol%. The orthologous average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between strain SZ9T and other genera within the family Caulobacteraceae were 64.50-66.62 %, 46.96-54.17 % and 27.70-31.70 %, respectively. Therefore, based on the results of phenotypic, chemotaxonomic and phylogenetic analyses, the isolated strain SZ9T could be distinguished from other genera, suggesting that it represents a novel species of a novel genus in the family Caulobacteraceae, for which the name Pseudaquidulcibacter saccharophilus gen. nov., sp. nov is proposed. The type strain is SZ9T (=CCTCC AB2021029T=KCTC 82788T).

Phenylobacterium hankyongense sp. nov., isolated from ginseng field soil.

A Gram-stain-negative, aerobic, non-motile, non-spore-forming and rod-shaped bacterial strain, designated HKS-05T, was isolated from ginseng field soil. This bacterium was characterized to determine its taxonomic position by using the polyphasic approach. HKS-05T grew at 10-37 °C and at pH 6.0-8.0 on R2A agar. On the basis of 16S rRNA gene sequence similarity, HKS-05T was shown to represent a member of the family Caulobacteraceaeand to be related to Phenylobacterium lituiforme FaiI3T (98.1 % sequence similarity), 'Phenylobacterium zucineum' HLK1 (97.9 %), Phenylobacterium muchangponense A8T (97.7 %), Phenylobacteriumcomposti 4T-6T (97.2 %) and Phenylobacterium immobile ET (97.1 %). The major respiratory quinone was Q-10 and the major fatty acids were summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c), C16 : 0, and summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c). The polar lipids were phosphatidylglycerol, unidentified glycolipids and unidentified polar lipids. The G+C content of the genomic DNA was 70.4 mol%. DNA-DNA relatedness values between HKS-05T and its closest phylogenetically neighbours were low. HKS-05T could be differentiated genotypically and phenotypically from the species of the genus Phenylobacterium with validly published names. The isolate therefore represents a novel species, for which the name Phenylobacteriumhankyongense sp. nov. is proposed, with the type strain HKS-05T (=KACC 18628T=LMG 30081T).

Phenylobacterium panacis sp. nov., isolated from the rhizosphere of rusty mountain ginseng.

A novel, Gram-stain-negative, rod-shaped bacterial strain, designated as DCY109T, was isolated from the rhizosphere of rusty mountain ginseng root located on Hwacheon mountain of Gangwon province, South Korea. 16S rRNA gene sequence analysis revealed that strain DCY109T belonged to the genus Phenylobacterium and was related closely to Phenylobacterium muchangponense KACC 15042T (98.2 % similarity), Phenylobacterium immobile DSM 1986T (96.9 %) and Phenylobacterium koreense KCTC 12206T (96.7 %). The predominant isoprenoid quinone was ubiquinone (Q-10) and the DNA G+C content was 66.9 mol%. The major polar lipids were phosphatidylglycerol, an unidentified glycolipid and an unidentified lipid. The major fatty acids (>10 %) were C16 : 0, summed feature 3 (which comprised C16 : 1ω7c and/or C16 : 1ω6c) and summed feature 8 (which comprised C18 : 1ω7c and/or C18 : 1ω6c). Mean DNA-DNA relatedness between strain DCY109T and its closest relative, P. muchangponense KACC 15042T, was 15.1±3.9 %. Based on the physiological, biochemical, chemotaxonomic and genetic analyses, strain DCY109T is considered to represent a novel species of the genus Phenylobacterium, for which the name Phenylobacterium panacis sp. nov. is proposed. The type strain is DCY109T (=KCTC 42749T=JCM 31045T).

Brevundimonas aveniformis sp. nov., a stalked species isolated from activated sludge.

A Gram-negative, rod-like, stalk-producing bacterium, designated strain EMB102(T), was isolated from activated sludge that performed enhanced biological phosphorus removal in a sequencing batch reactor. Cells without stalks were motile with single polar flagella, but cells that did produce stalks were non-motile and lacked polar flagella. Growth of strain EMB102(T) was observed at temperatures between 15 and 35 degrees C (optimum, 30 degrees C) and between pH 6.0 and 9.0 (optimum, pH 7.5-8.5). The predominant fatty acids of strain EMB102(T) were C(18 : 1) omega 7c, C(16 : 0) and C(15 : 0). The predominant polar lipid was phosphatidylglycerol. The G+C content of the genomic DNA was 64.1 mol% and the major quinone was Q-10. Comparative 16S rRNA gene sequence analyses showed that strain EMB102(T) formed a distinct phyletic lineage within the genus Brevundimonas. The levels of 16S rRNA gene sequence similarity between the type strains of Brevundimonas species ranged from 95.8 to 97.5 %. DNA-DNA relatedness levels between the EMB102(T) and closely related Brevundimonas species were below 15.0 %. On the basis of chemotaxonomic data and molecular properties, strain EMB102(T) represents a novel species within the genus Brevundimonas, for which the name Brevundimonas aveniformis sp. nov. is proposed. The type strain is EMB102(T) (=KCTC 12609(T)=DSM 17977(T)).