Niastella vici sp. nov., isolated from farmland soil

Abstract

Strain DJ57T is a Gram-reaction-negative, filamentous-shaped, non-flagellated, aerobic bacterium isolated from farmland soil in Hunan province of China. 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. 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 DJ57T was isolated from farmland soil near a lead and zinc mine (308 179 540 N 1138 289 160 E) in the city of Yueyang, Hunan province, PR China. The pH of the soil was pH 6.23 and the soil Pb and Zn concentrations were 127.6 and 54.41 mg kg 21 (dry weight soil), respectively. For the isolation, serial dilutions of the sample were spread on 1/10 tryptic soy agar (TSA; pH 7.3; Difco) and incubated at 28 8C for 7 days. Strain DJ57 T was obtained after several subcultivation cycles on 1/10 TSA. However, it was later noticed that the isolate grew better on R2A agar (pH 7.3; Difco).The nearly complete 16S rRNA gene fragment was amplified by PCR using universal primers 27F and 1492R as described by Fan et al. (2008), and the PCR products were sequenced by TsingKe Biological Technology (Beijing, China). The sequence (1491 bp) was compared with the available sequences in NCBI GenBank using the BLASTN program and its close relatives were extracted by the Ezbiocloud server (Kim et al., 2012). CLUSTAL X software (Thompson et al., 1997) was used to align the sequences. Maximum-parsimony (MP; Fitch, 1971), maximum-likelihood (ML;Felsenstein, 1981) and neighbour-joining (NJ; Saitou & Nei, 1987) trees were reconstructed by MEGA version 5.0 software (Tamura et al., 2011), and the Kimura twoparameter model was used (Kimura, 1980) to calculate the evolutionary distances. 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 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). Using MP and NJ methods, strain DJ57T also formed the same cluster with the four reference type strains (Figs S1 and S2, available in the online Supplementary Material).For morphological, biophysical and biochemical analyses, strains DJ57 T , N. populi CCTCC AB 208238 T , N. koreensis DSM 17620 T and N. yeon...

Niastella caeni sp. nov., isolated from activated sludge

“…Besides, 6062 CDSs and 56 RNAs were predicted. The DNA G+C content of strain HX-16-21 T acquired from the genome sequence was 43.5 mol%, a value within the range reported for strains belonging to the genus Niastella [1][2][3][4][5]. Additionally, among the 5 genomes of members in genus Niastella, strain HX-16-21 T possessed the smallest genome size.…”

“…The decomposition of gelatin, starch, chitin, Tween 40 and urea was tested on R2A agar supplemented with each substrate and the degradation results were achieved by visualizing clear zones around the colonies or staining phenomenon after dyeing with adequate staining solutions. Temperature range was investigated at 4,10,15,20,25,28,30,37,42 and 50 °C in R2A broth for 5 days. NaCl tolerance was investigated by growing the isolates in R2A broth supplemented with different NaCl concentrations (0, 0.1, 0.2, 0.5, 0.8, 1.0, 1.5, 2.0, 3.0 and 4.0 % w/v) for 5 days.…”

“…S2). The only detected respiratory quinone was menaquinone MK-7 (MK-7), which generally also existed in other members of the genus Niastella [1][2][3][4][5].…”

“…The genus Niastella, proposed by Weon et al in 2006 [1] and emended by Zhang et al in 2010 [2], belongs to the family Chitinophagaceae, phylum Bacteroidetes. Up to now, this genus comprises six species: Niastella koreensis [1], Niastella yeongjuensis [1], Niastella populi [2], Niastella gongjuensis [3], Niastella vici [4] and Niastella hibisci [5]. All of the Niastella species with validly published names are Gram-stain-negative, aerobic and filamentous rods.…”

“…Chemotaxonomically, members of the genus are characterized by menaquinone 7 (MK-7) as the predominant respiratory ubiquinone and iso-C 15 : 0 , iso-C 15 : 1 G and iso-C 17 : 0 3-OH as the main fatty acid components. The DNA G+C content ranges from 41.4 to 45.8 mol% [1][2][3][4][5]. In this study, we characterize strain HX-16-21 T , which was isolated from an activated sludge sample collected from an agricultural chemical plant.…”