Halosimplex carlsbadense gen. nov., sp. nov., a unique halophilic archaeon, with three 16S rRNA genes, that grows only in defined medium with glycerol and acetate or pyruvate

Abstract

A halophilic archaeon has been isolated from unsterilized salt crystals taken from the 250-million-year-old Salado formation in southeastern New Mexico. This microorganism grows only on defined media supplemented with either a combination of acetate and glycerol, glycerol and pyruvate, or pyruvate alone. The archaeon is unable to grow on complex media or to use carbohydrates, amino acids, fats, proteins, or nucleic acids for growth. Unlike other halophilic microbes, this organism possesses four glycolipids, two of which may be novel. The microbe is unique in that it has three dissimilar 16S rRNA genes. Two of the three genes show only 97% similarity to one another, while the third gene possesses only 92%-93% similarity to the other two. Inferred phylogenies indicate that the organism belongs to a deep branch in the line of Haloarcula and Halorhabdus. All three lines of taxonomic evidence: phenotype, lipid patterns, and phylogeny, support creation of a new genus and species within the halophilic Archaea. The name suggested for this new genus and species is Halosimplex carlsbadense. The type strain is 2-9-1(T) (= ATCC BAA-75 and JCM 11222) as written in the formal description.

Halovenus aranensis gen. nov., sp. nov., an extremely halophilic archaeon from Aran-Bidgol salt lake

“…The minor phospholipids associated with this novel strain Table 1. Differential characteristics of strain EB27 T and strains of type species of closely related genera within the order Halobacteriales Taxa: 1, strain EB27 T (data from this study); 2, Halalkalicoccus tibetensis DS12 T (Xue et al, 2005); 3, Halosimplex carlsbadense 2-9-1 T (Vreeland et al, 2002); 4, Halorhabdus utahensis AX-2 T (Wainø et al, 2000); 5, Haloterrigena turkmenica VKM B-1734 T (Ventosa et al, 1999); and 6, Halobacterium salinarum DSM 3754 T (Grant et al, 2001 were not detected in the haloalkaliphilic genus Halalkalicoccus, to which it is closely related phylogenetically (Xue et al, 2005). This result indicates a difference between strain EB27 T and its closest relatives in the family Halobacteriaceae.…”

Growth Kinetics of Extremely Halophilic Archaea (Family Halobacteriaceae ) as Revealed by Arrhenius Plots

“…In addition to exhibiting halophilicity, four genera (Natronococcus, Natronomonas, Natronorubrum, and Natronobacterium) are also alkaliphilic, growing optimally between pH 9.5 and 10.0 (20). These organisms have been isolated from a wide variety of environments, including the sediment of a cold, hypersaline lake in Antarctica (Halorubrum lacusprofundi) (3), the Dead Sea (Haloferax volcanii) (16), the Great Salt Lake (Halorabdus utahensis) (31), a hypersaline soda lake in Egypt (Natronomonas pharaonis) (27), and a salt crystal from a Permian halite deposit (Halosimplex carlsbadense) (30). There is also a report of haloarchaeal 16S rDNA amplified from inside a black smoker (28), but no haloarchaeons have been cultured from this source.…”

Halosiccatus urmianus gen. nov., sp. nov., a haloarchaeon from a salt lake

“…S5). The presence of PGS in this new archaeon differentiated it from the related taxon Halosimplex, which did not contain PGS (Vreeland et al, 2002). Also, with respect to the number of glycolipids and minor phospholipids, this strain could be distinguished from two other phylogenetically closely related taxa, Halomicrobium and Halomicroarcula (Oren et al, 2002;Echigo et al, 2013).…”