Niastella populi sp. nov., isolated from soil of Euphrates poplar (Populus euphratica) forest, and emended description of the genus Niastella

Abstract

Niastella populi sp. nov., isolated from soil of Euphrates poplar (Populus euphratica) forest, and emended description of the genus Niastella A novel bacterial strain, designated THYL-44 T , was isolated from the soil of a Euphrates poplar (Populus euphratica) forest in Xinjiang, China. The cells were strictly aerobic, Gram-stainingnegative, non-flagellated, non-motile and filamentous. Growth occurred at 17-37 6C (optimum 30 6C), at pH 5.0-8.0 (optimum pH 7.0) and with 0-1 % NaCl (w/v; optimum 0 %). Flexirubin pigments were not produced. A phylogenetic analysis based on 16S rRNA gene sequences revealed that strain THYL-44 T was closely related to Niastella koreensis KACC 11465 T (95.5 % sequence similarity). The major respiratory quinone was MK-7 and the predominant cellular fatty acids were iso-C 15 : 0 (28.6 %), iso-C 17 : 0 3-OH (23.9 %) and iso-C 15 : 1 G (17.4 %). The DNA G+C content was 45.2 mol%. Therefore, the phylogenetic, physiological and chemotaxonomic data demonstrated that strain THYL-44 T represents a novel species of the genus Niastella, for which the name Niastella populi sp. nov. is proposed. The type strain is THYL-44 T (5CCTCC AB 208238 T 5KCTC 22560 T ). On the basis of new data, an emended description of the genus Niastella is also proposed.The genus Niastella, containing Niastella koreensis (type species) and Niastella yeongjuensis, was proposed by Weon et al. (2006) for bacterial strains isolated from soil cultivated with Korean ginseng. These organisms are Gram-staining-negative, aerobic, filamentous bacteria that are motile by gliding, that do not produce flexirubin pigments and do not reduce nitrate. Their cellular fatty acids include large amounts of iso-C 15 : 0 , iso-C 15 : 1 G and iso-C 17 : 0 3-OH and their major respiratory quinone is MK-7. Phylogenetically, the genus Niastella is a member of the family Chitinophagaceae, phylum Bacteroidetes (http:// www.bacterio.net).In the present study, a novel member of the genus Niastella was characterized. Strain THYL-44 T was isolated from the soil of a Euphrates poplar (Populus euphratica) forest (84 u 159~84 u 309 E, 40 u 09~40 u 559 N) in Xinjiang, China. The soil sample was diluted with sterile water and the dilutions were plated onto 0.16TSA (tryptic soy agar; Difco) plates. The strain was isolated after incubation at 30 u C for one week. However, it was later noticed that the isolate grew better on R2A agar (Difco).Cell morphology was examined by phase-contrast microscopy (BX51; Olympus) and transmission electron microscopy (8100; Hitachi), using cells negatively stained with 2 % (w/v) phosphotungstic acid after air drying. Gram staining was carried out according to the classical Gram procedure described by Doetsch (1981). Motility was examined according to the method of Bernardet et al. (2002). Growth at 4, 17, 22, 25, 30, 37, 42 and 50 u C and at pH 5.0-10.0 (at 1.0 pH unit intervals) was tested after 5 days of incubation in R2A broth. The pH was adjusted using 1 M HCl or 1 M NaOH and the broth was then filter-sterilized at 0.2 ...

Niastella vici sp. nov., isolated from farmland soil

“…16S rRNA gene sequence analysis demonstrated that this isolate belonged to the genus Niastella, with 95.83 % nucleotide identity to Niastella populi THYL-44 T , while the similarities to other type strains of species of the genus Niastella were less than 95.76 %. The major isoprenoid quinone was menaquinone-7 and the major fatty acids (.5 %) were iso-C 15 : 0 , iso-C 17 : 0 3-OH, iso- Zhang et al (2010). Members of the genus Niastella are Gram-reaction-negative, strictly aerobic, long, filamentous rods.…”

“…Bar, 2 mm. (Weon et al, 2006;Zhang et al, 2010;Kim et al, 2015), but iso-C 16 : 0 was only found in strain DJ57 T (Table 2).…”

“…So far, this genus consists of the type strains of four species, all isolated from soil: Niastella koreensis GR20-10 T (Weon et al, 2006), Niastella yeongjuensis GR20-13 T (Weon et al, 2006), Niastella populi THYL-44 T (Zhang et al, 2010) and Niastella gongjuensis 5GH22-11 T (Kim et al, 2015). The genus was first proposed by Weon et al (2006) and emended by Zhang et al (2010). Members of the genus Niastella are Gram-reaction-negative, strictly aerobic, long, filamentous rods.…”

“…The DNA G+C content range is 41.4-45.8 mol%. The major respiratory quinone is menaquinone-7 (MK-7) and the predominant cellular fatty acids are iso-C 15 : 0 , iso-C 15 : 1 G and iso-C 17 : 0 3-OH (Weon et al, 2006;Zhang et al, 2010;Kim et al, 2015). In this study, strain DJ57…”

“…Bootstrap analysis was used to estimate tree topologies according to 1000 resamplings (Felsenstein, 1985). The adjacent strains of DJ57 T in the ML tree were N. populi THYL-44 T (Zhang et al, 2010), N. koreensis GR20-10 T (Weon et al, 2006), N. gongjuensis 5GH22-11 T (Kim et al, 2015) and N. yeongjuensis GR20-13 T (Weon et al, 2006), and their 16S rRNA gene sequence identities were 95.83, 95.76, 95.64 and 95.16 %, respectively (Fig. 1).…”