Pontibacter akesuensis sp. nov., isolated from a desert soil in China

Abstract

A Gram-negative, non-motile, rod-shaped bacterium, designated strain AKS 1 T , was isolated from a desert soil sample collected from Akesu, XinJiang Province, China. A taxonomic study, including phylogenetic analysis based on 16S rRNA gene sequences and phenotypic characteristics, was performed on the novel isolate. The predominant menaquinone of strain AKS 1 T was MK-7. The major fatty acids included i-C 15 : 0 , ai-C 17 : 1 B/i-C 17 : 1 I and i-C 17 : 0 3-OH. The G+C content of the DNA was 51.4 mol%. Based on the results of phenotypic and genotypic characteristics, strain AKS 1 T should be assigned as representing a novel species of the genus Pontibacter, for which the name Pontibacter akesuensis is proposed. The type strain is AKS 1 T (=KCTC 12758 T =CCTCC AB 206086 T ).The genus Pontibacter belongs to the phylum Bacteroidetes and was first described by Nedashkovskaya et al. (2005b) based on a single isolate from an unidentified sea anemone. The main characteristics of members of the phylum Bacteroidetes include the ability to move by gliding (many lack motility), a rod-shaped or ring-shaped morphology, possession of Gram-negative cell walls and pigmentation. The majority of the members of the phylum Bacteroidetes have been isolated from seawater, sediment or algae. Some marine bacteria of the phylum Bacteroidetes possess menaquinone 7 (MK-7) as their main respiratory quinone (Bowman et al., 2003; Brettar et al., 2004a, b; Nedashkovskaya et al., , 2004 Nedashkovskaya et al., , 2005aRaj & Maloy, 1990;Van Trappen et al., 2004;Yi & Chun, 2004;Yoon et al., 2004Yoon et al., , 2005a. The present investigation was designed to establish the taxonomic position of a novel isolate that formed a common clade with the genus Pontibacter within the phylum Bacteroidetes. Although the novel isolate has some properties characteristic of the phylum Bacteroidetes, it also has many special properties that are distinct from other members of the phylum. Genotypic and phenotypic data show that the strain represents a novel species of the genus Pontibacter.Strain AKS 1 T was isolated from a desert soil sample collected from Akesu, XinJiang Province, north-west China, by using the traditional dilution plating method. LB agar (Sambrook & Russell, 2002) was used for selective isolation and cultures were incubated at 30 uC for 1 week. The novel strain was maintained on LB agar slants at 4 u C and as glycerol suspensions (20 %, v/v) at 280 uC. Biomass for molecular systematic and chemotaxonomic studies was obtained after incubation in LB at 30 uC for 2 days in shake flasks (about 150 r.p.m.), with the pH adjusted to pH 7.8 using NaOH.Cell morphology of the novel isolate was observed by light microscopy (BH2; Olympus) and by transmission electron microscopy (H-7650; Hitachi) after 24 h growth on LB medium. Acid production from carbohydrates was tested using the media and methods described by Gordon et al. (1974). Sole carbon and sole carbon/nitrogen source utilization was investigated using the Biolog GN2 Microplate system (Nedashkovsk...

Pontibacter ruber sp. nov. and Pontibacter deserti sp. nov., isolated from the desert

“…Starch, gelatin and chitin are not hydrolysed, while casein is hydrolysed. (Zhou et al, 2007); 9, P. niistensis NII-0909 T (Dastager et al, 2010); 10, P. ramchanderi LP43 T (Singh et al, 2013b); 11, Pontibacter xinjiangensis 311-10 T (Wang et al, 2010); 12, Pontibacter saemangeumensis GCM0142 T (Kang et al, 2013); 13, Pontibacter toksunensis ZLD-7 T (Zhang et al, 2013); 14, Pontibacter indicus LP100 T (Singh et al, 2013a). Phosphatydylethanolamine is the major polar lipid of all strains; all strains are positive for catalase; all strains are negative for denitrification activity.…”

“…Most members of this genus have gliding motility and phosphatidylethanolamine as a major polar lipid (Nedashkovskaya et al, 2005;Subhash et al, 2013a;Dwivedi et al, 2013;Kang et al, 2013). At the time of writing, 13 species with validly published names had been described, with members of the species commonly isolated from habitats such as solar salterns, hexachlorocyclohexane (HCH) dump sites, rhizospheric soils, desert soils and sea water (Subhash et al, 2013b;Dwivedi et al, 2013;Xu et al, 2012;Raichand et al, 2011;Zhou et al, 2007;Nedashkovskaya et al, 2005;Kang et al, 2013). Five species were originally isolated in India, including: Pontibacter niistensis NII-0909 T (Dastager et al, 2010), Pontibacter lucknowensis DM9 T (Dwivedi et al, 2013), Pontibacter odishensis JC130 T (Subhash et al, 2013b), Pontibacter ramchanderi LP43 T (Singh et al, 2013b) and Pontibacter indicus LP100 T (Singh et al, 2013a).…”

Flavobacterium tistrianum sp. nov., a gliding bacterium isolated from soil

“…Growth was examined on trypticase soy agar (TSA, BD), Luria Bertani agar (LB), yeast extract malt extract agar (ISP Medium 2, BD), tryptone yeast extract agar (per liter distilled water: 3 g tryptone, 5 g yeast extract, 5 g glucose, 15 g agar; pH 7.0), nutrient agar and CYEA. Salt tolerance was examined using LB broth containing 0, 1, 2, 3, 4 and 5 % NaCl; LB broth was adjusted to pH 5.0-11.0 (using increments of 0.5 pH unit) to determine the optimal pH for growth (Zhou et al, 2007). Catalase activity was tested by production of oxygen bubbles when 5 % (v/v) H 2 O 2 was added to fresh cells.…”

Pontibacter xinjiangensis sp. nov., in the phylum ‘Bacteroidetes’, and reclassification of [Effluviibacter] roseus as Pontibacter roseus comb. nov.

“…At the time of writing, Pontibacter species with validly published names comprise Pontibacter actiniarum, isolated from marine actinians (Nedashkovskaya et al, 2005), and Pontibacter akesuensis (Zhou et al, 2007) During the course of studying the bacterial communities associated with soil in Xinjiang, China, bacterial strain 311-10 T was isolated. The strain appeared as pinkpigmented, circular, convex, shiny colonies with a smooth surface after 48 h cultivation at 30 uC on 0.36 marine agar 2216 (MA; Difco).…”