Amphiplicatus metriothermophilus gen. nov., sp. nov., a thermotolerant alphaproteobacterium isolated from a hot spring

Abstract

A thermotolerant, Gram-strain-negative, non-spore-forming and strictly aerobic bacterium, designated GU51 T , was isolated from Guhai hot spring in Jimsar county, Xinjiang province, northwest China. Each cell of strain GU51 T consisted of an oval body and two symmetrical long (3-6 mm) prosthecae. The strain moved by polar flagellum. Oxidase and catalase were produced. Strain GU51 T grew within the ranges of 37-65 6C (optimum 48-50 6C), 0.5-7.5 % (w/v) NaCl (optimum 2-3 %) and pH 6.0-9.0 (optimum pH 7.5). The major respiratory quinone detected was ubiquinone 10 (U-10) and the genomic DNA G+C content was 66.7±0.4 mol%. Major fatty acids (.5 %) were C 16 : 0 , C 18 : 1 v7c and 11-methyl C 18 : 1 v7c. The polar lipids consisted of diphosphatidylglycerol, five glycolipids, phosphatidylglycerol and an unknown phospholipid. Phylogenetic analysis showed the closest relatives of strain GU51 T were members of the genus Parvularcula with 92.3 % 16S rRNA gene sequence similarity. On the basis of this polyphasic taxonomic characterization, it is suggested that strain GU51 T represents a novel species of a new genus in the family 'Parvularculaceae', for which the name Amphiplicatus metriothermophilus gen. nov., sp. nov. is proposed. The type strain of the type species is GU51 T (5CGMCC 1.12710 T 5JCM 19779 T ).The family 'Parvularculaceae' belongs to the order 'Parvularculales'. At the time of writing, the order comprises one family and the family comprises a single genus, Parvularcula, which was established by Cho & Giovannoni (2003) , 2013). The isolates belonging to the genus Parvularcula were obtained from seawater, a coastal hot spring and a soft coral, respectively, which indicates that the evolutionary cluster had a high similarity of habitat and metabolism pathways. All three species of the genus are mesophilic, Gram-strain-negative and non-spore-forming. Phylogenetic tree analysis revealed that a novel thermotolerant strain, designated GU51 T , was closely related to the genus Parvularcula. However, it was clearly distinct from this genus by high sequence divergence values and the significant differences of morphological and chemotaxonomic characteristics. In the present study, we report the results of a polyphasic taxonomy on strain GU51 T and propose that strain GU51 T represents a novel species of a new genus in the family 'Parvularculaceae'. Strain GU51 T was isolated from the Guhai hot spring (44 u 459 N 88 u 499 E) in Jimsar county, Xinjiang province, north-west China. The highest temperature in situ was measured to be 75 u C. Guhai hot spring, which means ancient sea, was discovered accidentally during oil exploration in October1982 (official reports). A water sample from the spring was collected and transported without temperature control and then stored at room temperature in the laboratory until used. 0.52 g crystals were produced from evaporation of 20 ml water sample at 55 u C in the laboratory, and were sent for detection. According to the analysis results of X-ray Energy Dispersive Spectroscopy (EDS) ...

Aquisalinus flavus gen. nov., sp. nov., a member of the family Parvularculaceae isolated from a saline lake

“…The respiratory quinones were Q-10 (66 %) and Q-11 (34 %). Q-10 as a major quinone was in accordance with all members of the family Parvularculaceae (Arun et al, 2009;Cho & Giovannoni, 2003;Yu et al, 2013;Zhen-Li et al, 2014). Nevertheless, strain D11M-12 T could clearly be distinguished from all members of the family Parvularculaceae by the presence of Q-11 as one of the major quinones (Table 1).…”

“…The family Parvularculaceae is the sole family of the order Parvularculales within the class Alphaproteobacteria and consists of two genera, Parvularcula and Amphiplicatus, which were proposed by Cho & Giovannoni (2003) and Zhen-Li et al (2014), respectively. The genus Parvularcula comprises four species, Parvularcula bermudensis (Cho & Giovannoni, 2003), P. lutaonensis (Arun et al, 2009), P. dongshanensis (Yu et al, 2013) and 'P.…”

“…oceani' (Li et al, 2014a(Li et al, , 2014b, which were isolated from seawater, coastal hot spring water, soft coral and deep-sea water, respectively. The genus Amphiplicatus contains only one species, Amphiplicatus metriothermophilus (Zhen- Li et al, 2014), obtained from a hot spring in Xinjiang Province, north-west China. Members of the family Parvularculaceae are characterized as Gram-stain-negative, oxidase-positive, non-spore-forming, strictly aerobic, chemoheterotrophic and motile by means of a single polar flagellum, containing summed feature 8 (C 18 : 1 v7c and/or C 18 : 1 v6c) as the major fatty acid and Q-10 as the major respiratory quinone (Cavalcanti & Thompson, 2014;Zhen-Li et al, 2014).…”

“…The genus Amphiplicatus contains only one species, Amphiplicatus metriothermophilus (Zhen- Li et al, 2014), obtained from a hot spring in Xinjiang Province, north-west China. Members of the family Parvularculaceae are characterized as Gram-stain-negative, oxidase-positive, non-spore-forming, strictly aerobic, chemoheterotrophic and motile by means of a single polar flagellum, containing summed feature 8 (C 18 : 1 v7c and/or C 18 : 1 v6c) as the major fatty acid and Q-10 as the major respiratory quinone (Cavalcanti & Thompson, 2014;Zhen-Li et al, 2014). During a survey of bacterial diversity of lakes in the Qaidam basin, Qinghai Province, China, a novel Parvularculaceae-like bacterium, strain D11M-2 T , was isolated from a surface water sample of a saline lake, Lake Dasugan.…”

“…Genomic ). All data were from this study except for DNA G+C content and the major respiratory quinone for the two reference genera (Arun et al, 2009;Cho & Giovannoni, 2003;Li et al, 2014aLi et al, , 2014bYu et al, 2013;Zhen-Li et al, 2014). +, Positive; 2, negative; W, weakly positive; V, variable among species.…”