Halomonas xinjiangensis sp. nov., a halotolerant bacterium isolated from a salt lake

Abstract

A novel bacterium, TRM 0175 T , belonging to the genus Halomonas, was isolated from a soil sample taken from a salt lake in Xinjiang Province, north-west China. The isolate was Gramnegative, aerobic, rod-shaped and motile by means of peritrichous flagella. It was catalasepositive and oxidase-negative. Growth occurred at NaCl concentrations of 0-20 % (optimum at 10-13 %), at 15-50 6C (optimum at 37 6C) and at pH 6.0-9.0 (optimum at pH 7.0). Metabolism was respiratory with oxygen as terminal electron acceptor. Acid was produced from D-ribose, D-and L-arabinose, D-xylose, D-galactose, D-mannose, L-rhamnose, cellobiose, maltose, trehalose and D-and L-fucose and was produced weakly from aesculin. The predominant ubiquinone was Q-9. The major fatty acids were C 18 : 1 v7c and C 19 : 0 cyclo v8c. The G+C content of the genomic DNA was 60.0 mol%. The family Halomonadaceae currently includes four genera of halophilic bacteria, Halomonas, Chromohalobacter, Cobetia and Modicisalibacter, and three genera of nonhalophilic bacteria, Carnimonas, Halotalea and Zymobacter (Franzmann et al., 1988;Ventosa et al., 1989;Okamoto et al., 1993;Dobson & Franzmann, 1996;Garriga et al., 1998;Arahal et al., 2002Arahal et al., , 2007Ntougias et al., 2007; Ben Ali Gam et al., 2007). The genus Halomonas was proposed by Vreeland et al. (1980), with Halomonas elongata as the type species. At the time of writing, the genus Halomonas contained the greatest number of species (54 species with validly published names; http://www.bacterio.cict.fr/ h/halomonas.html) of all genera in the family Halomonadaceae.Strain TRM 0175 T , which belongs to the genus Halomonas, was isolated from a soil sample from Lop Nur salt lake (40 u 239 N 90 u 189 E; 778 m altitude) in Xinjiang Province, north-west China. The high salinity (30.5 %), low nutrient levels, dry climate and high UV intensity make it an extreme environment. A soil sample (approx. 100 g) was collected from Lop Nur salt lake in autumn. The temperature and pH of the soil sample, measured with portable meters, were 16.2 u C and pH 7.4, respectively. The sample was isolated on trypticase soy agar (TSA) containing 15 % (w/v) NaCl by using a tenfold dilution series method. The organism was grown and maintained at 37 u C on TSA containing 10 % (w/v) NaCl.Cell morphology and motility were examined by optical microscopy (Olympus BX40) and transmission electron microscopy (Philips CM200). For NaCl tolerance experiments, growth was studied at 37 u C in TSA containing 0, 0.5, 1, 3, 5, 8, 10, 13, 15, 18, 20, 25 and 30 % (w/v) NaCl. Growth was investigated on TSA containing 10 % (w/v) NaCl at 5-55 u C (at intervals of 5 u C) and at pH 4-12 (at The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain TRM 0175 T is EU822512.Phylogenetic trees based on maximum-parsimony and maximumlikelihood analysis of the 16S rRNA gene sequences and a transmission electron micrograph of cells of strain TRM 0175 T are available as supplementary material with the online version of this paper. Mata et al. (...

Microbial diversity and activity in hypersaline high Arctic spring channels

“…With the exception of Cyanobacteria, all LH source phyla were represented in the channel as well as several additional phyla, including an abundance of Actinobacteria, that were not detected in the LH source sediments. Phylotypes for Halomonas, Gillisia, and Marinobacter, which are common bacterial genera in cold Arctic and Antarctic environments (Bowman et al 1997;Bowman and Nichols 2005;Brinkmeyer et al 2003;Franzmann et al 1987;Guan et al 2009;Zhang et al 2008), were detected in both the LH source (Niederberger et al 2010) and channel sediments. Representatives of sulfurcycling bacteria were also detected in channel sediments that were not found in the source sediments indicating that various sulfur intermediates were important metabolic substrates within the LH channel including sulfite (Sulfitobacter sp.…”

Brevibacterium salitolerans sp. nov., an actinobacterium isolated from salt-lake sediment

“…In the present study, an actinobacterial isolate, designated TRM 415 T , from a sediment sample collected from Lop Nur salt lake in Xinjiang province, north-west China, was investigated by means of a polyphasic taxonomic approach. The lake environment and precise sampling site location were described previously (Guan et al, 2010).…”

“…In the present study, an actinobacterial isolate, designated TRM 415 T , from a sediment sample collected from Lop Nur salt lake in Xinjiang province, north-west China, was investigated by means of a polyphasic taxonomic approach. The lake environment and precise sampling site location were described previously (Guan et al, 2010).The sample was isolated on GT2 medium using a 10-fold dilution series method with incubation at 37 u C. The GT2 medium contained (g l 21 ): glucose (10), yeast extract (1), tryptone (0.5), CaCO 3 (1), NaCl (50), KCl (30), MgCl 2 (10) and agar (16). The medium was adjusted to pH 7.0-7.5.…”

Halomonas garicola sp. nov., isolated from saeu-jeot, a Korean salted and fermented shrimp sauce

“…At the time of writing, the family Halomonadaceae belonging to the class Gammaproteobacteria consists of nine halophilic genera with validly published names (Aidingimonas, Chromohalobacter, Cobetia, Halomonas, Halotalea, Kushneria, Modicisalibacter, Salinicola and Larsenimonas) (Vreeland et al, 1980;Ventosa et al, 1989;Mellado et al, 1995;Arahal et al, 2002;Arahal & Ventosa, 2006;Gam et al, 2007;Ntougias et al, 2007;Sánchez-Porro et al, 2009;Wang et al, 2009;Leó n et al, 2015) that are capable of growth in saline environments with 15 % (w/v) salt concentrations plus two nonhalophilic genera (Carnimonas and Zymobacter) (Okamoto et al, 1993;Garriga et al, 1998). Among the genera, the genus Halomonas including Gram-stain-negative, moderately halophilic, aerobic or facultatively aerobic rod-shaped bacteria is the largest genus, which includes 90 species with validly published names that have been isolated from diverse saline environments such as solar salterns, salt lakes, fermented seafood, sea squirts, sea ice, hydrothermal vents and saline-alkali soil (Vreeland et al, 1980;Ventosa et al, 1998;Romanenko et al, 2002;Yoon et al, 2002;Kaye et al, 2004;Lim et al, 2004;Arenas et al, 2009;Kim et al, 2010;Guan et al, 2010;Guzmán et al, 2010;Jeong et al, 2013;Miao et al, 2014). Because members of the genus Halomonas are phenotypically diverse and have an unusually wide range of DNA G+C contents (52-74.3 mol%), they are being split into different genera (Arahal et al 2002).…”