Halopeptonella vilamensis gen. nov, sp. nov., a halophilic strictly aerobic bacterium of the family Ectothiorhodospiraceae

A Gram-negative, halophilic, heterotrophic, rod-shaped, non-spore-forming bacterium (SV525T) was isolated from the sediment of a hypersaline lake located at 4600 m above sea level (Laguna Vilama, Argentina). Strain SV525T was strictly aerobic and formed pink-to-magenta colonies. Growth occurred at 10–35 °C (optimum 25–30 °C), at pH levels 6.0–8.5 (optimum 7.0) and at NaCl concentrations of 7.5–25 % (w/v) with an optimum at 10–15 % (w/v). The strain required sodium and magnesium but not potassium ions for growth. Grows with tryptone, or Bacto Peptone as sole carbon and energy source and requires yeast extract for growth. It produced catalase and oxidase. The predominant ubiquinone was Q-8 and the major fatty acids comprised C18:1ω7c, C16:0 and C18:0. The DNA G+C content was 60.4 mol% and its polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and a phosphoglycolipid. Phylogenetic analysis based on 16S rRNA gene indicated that strain SV525T belongs to the family Ectothiorhodospiraceae within the class Gammaproteobacteria. On the basis of phylogenetic and phenotypic data, SV525T represents a novel genus and species, for which the name Halopeptonella vilamensis gen. nov., sp. nov. is proposed. The type strain is SV525T (=DSM 21056T =JCM 16388T =NCIMB 14596T).Fil: Menes, Rodolfo Javier. Universidad de la Republica Facultad de Quimica; UruguayFil: Viera, Claudia Elizabeth. Universidad de la Republica Facultad de Quimica; UruguayFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; ArgentinaFil: Seufferheld, Manfredo Jose. University of Illinois. Urbana - Champaign; Estados Unido

Halomonas vilamensis sp. nov., isolated from high-altitude Andean lakes

A Gram-negative, aerobic, rod-shaped, non-spore-forming bacterium (SV325T) was isolated from the sediment of a hypersaline lake located at 4600 m above sea level (Laguna Vilama, Argentina). Strain SV325T formed cream-to-pink colonies, was motile and moderately halophilic, and grew at NaCl concentrations of 1-25 % (w/v) with an optimum at 5-10 % (w/v). Growth occurred at 5-40 degrees C (optimum around 30 degrees C) and at pH levels 5.0-10.0 (optimum 7.0-8.0). The bacteria does not produce exopolysaccharides, stained positively for intracellular polyphosphate granules but not for poly-beta-hydroxyalkanoates It produced catalase and oxidase, reduced nitrate to nitrite, hydrolyzed gelatin, did not produce acids from sugars, and utilized a limited range of substrates as carbon and energy sources: acetate, caproate, fumarate, DL-beta-hydroxybutyrate, malate, maleate, malonate and succinate. The predominant ubiquinones were Q-9 (92.5 %) and Q-8 (7.5 %), the major fatty acids were C19:0 cyclo omega8c, C16:0, C17:0 cyclo and C16:1 omega7c/15 iso 2-OH, and the DNA G+C content was 55.0 mol%. Phylogenetic analyses based on 16S rRNA gene indicated that strain SV325T belongs to the genus Halomonas in the class Gammaproteobacteria. Physiological and biochemical tests allowed phenotypic differentiation of strain SV325T from closely related, valid, published species names and therefore represents a new species; the name Halomonas vilamensis sp. nov. is proposed for this species, with type strain SV325T (=DSM 21020T =LMG 24332T).Fil: Menes, Rodolfo Javier. Universidad de la Republica. Facultad de Química y Facultad de Ciencias; UruguayFil: Viera, Claudia Elizabeth. Universidad de la Republica. Facultad de Química y Facultad de Ciencias; UruguayFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Planta Piloto de Procesos Industriales Microbiológicos (i); ArgentinaFil: Seufferheld, Manfredo Jose. University Of Illinois At Urbana; Estados Unido

The structure of the lipid a from the halophilic bacterium Spiribacter salinus M19-40T

The study of the adaptation mechanisms that allow microorganisms to live and proliferate in an extreme habitat is a growing research field. Directly exposed to the external environment, lipopolysaccharides (LPS) from Gram-negative bacteria are of great appeal as they can present particular structural features that may aid the understanding of the adaptation processes. Moreover, through being involved in modulating the mammalian immune system response in a structure-dependent fashion, the elucidation of the LPS structure can also be seen as a fundamental step from a biomedical point of view. In this paper, the lipid A structure of the LPS from Spiribacter salinus M19-40T, a halophilic gamma-proteobacteria, was characterized through chemical analyses and matrix-assisted laser desorption ionization (MALDI) mass spectrometry. This revealed a mixture of mono- and bisphosphorylated penta- to tri-acylated species with the uncommon 2 + 3 symmetry and bearing an unusual 3-oxotetradecaonic acid