Haladaptatus paucihalophilus gen. nov., sp. nov., a halophilic archaeon isolated from a low-salt, sulfide-rich spring

Abstract

Two novel strains of halophilic archaea, DX253T and GY252, were isolated from Zodletone Spring, a low-salt, sulfide- and sulfur-rich spring in south-western Oklahoma, USA. The cells were cocci or coccobacilli and occurred singly or in pairs. The two strains grew in a wide range of salt concentrations (0.8–5.1 M) and required at least 5 mM Mg2+ for growth. The pH range for growth was 5–7.5 and the temperature range was 25–45 °C. In addition to having the capacity to grow at relatively low salt concentrations, cells remained viable in distilled water after prolonged incubation. The two diether phospholipids that are typical of members of the order Halobacteriales, phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester, were present. Phosphatidylglycerol sulfate and two unidentified glycolipids were also detected. Each strain had two distinct 16S rRNA gene sequences that were only 89.5–90.8 % similar to sequences from the most closely related cultured and recognized species within the order Halobacteriales. The DNA G+C content of the type strain was found to be 60.5 mol%. The closest relatives were clones and uncharacterized isolates obtained from coastal salt-marsh sediments with salinities equivalent to that of seawater. The physiological, biochemical and phylogenetic differences between strains DX253T and GY252 and other previously described genera of extremely halophilic archaea suggest that these novel strains represent a novel species and genus within the family Halobacteriaceae, for which the name Haladaptatus paucihalophilus gen. nov., sp. nov. is proposed. The type strain is DX253T (=JCM 13897T=DSM 18195T=ATCC BAA-1313T=KCTC 4006T).

Halosarcina pallida gen. nov., sp. nov., a halophilic archaeon from a low-salt, sulfide-rich spring

“…In the present study, we report on the isolation and characterization of strain BZ256 T from a sulfur-and sulfide-rich spring in south-western Oklahoma, USA. We suggest that this strain represents a novel species of a new genus within the order Halobacteriales.The location and geochemical characteristics of the spring, as well as its archaeal diversity and the rationale for encountering halophilic archaea in this seemingly low-salt environment, have been described by Elshahed et al (2004b) and Savage et al (2007). Sampling and isolation procedures were as described in detail by Savage et al (2007).…”

“…Physiological tests were conducted by using an HMD liquid or solid (2.0 % agar) medium with sucrose (0.5 g l 21 ) as the carbon source, 180 g NaCl l 21 and 25 mM HEPES, unless otherwise stated. The minimum NaCl concentration necessary to stabilize cells in distilled water or HMD medium was tested as described by Savage et al (2007). The NaCl concentrations tested ranged from 0 to 7 %.…”

“…Recently, the extent of the family has been undergoing rapid expansion, with the description (as of June 2007) of five new genera and 20 novel species since 2006. This expansion has been due not only to the identification of novel taxa isolated from well-known hypersaline environments, such as the genera Halovivax, Halostagnicola, Haloplanus and Haloquadratum (Castillo et al, 2006a, b;Bardavid et al, 2007;Burns et al, 2007), but also to the recognition that members of the Halobacteriales can grow within saline microniches in non-saline environments at relatively low salt concentrations (Elshahed et al, 2004a;Savage et al, 2007). In addition, recent studies have reported the isolation of novel halobacterial strains (Purdy et al, 2004;Fukushima et al, 2007) or the detection of novel Halobacteriales-affiliated 16S rRNA gene sequences from moderate-to low-salinity systems (Munson et al, 1997;Takai et al, 2001;Walsh et al, 2005).…”

“…The location and geochemical characteristics of the spring, as well as its archaeal diversity and the rationale for encountering halophilic archaea in this seemingly low-salt environment, have been described by Elshahed et al (2004b) and Savage et al (2007). Sampling and isolation procedures were as described in detail by Savage et al (2007).…”

Haloterrigena salina sp. nov., an extremely halophilic archaeon isolated from a salt lake

“…Extremely halophilic archaea, members of the Halobacteriaceae, have been isolated from various hypersaline environments and are classified into 26 genera (Tindall et al, 1984;Torreblanca et al, 1986;McGenity & Grant, 1995;Oren et al, 1995Oren et al, , 2002Kamekura & Dyall-Smith, 1995;Kamekura et al, 1997;McGenity et al, 1998;Montalvo-Rodriguez et al, 1998;Ventosa et al, 1999;Xu et al, 1999;Wainø et al, 2000;Grant, 2001a, b;Hezayen et al, 2002;Vreeland et al, 2002, Itoh et al, 2005Xue et al, 2005;Castillo et al, 2006a, b;Savage et al, 2007;Burns et al, 2007;Bardavid et al, 2007;Gutiérrez et al, 2007). The genus Haloterrigena was established by Ventosa et al (1999) to accommodate the species Haloterrigena turkmenica (formerly Halococcus turkmenicus).…”