Alkaliphilic heliobacterium Heliorestis baculata sp. nov. and emended description of the genus Heliorestis

Abstract

A rod-shaped heliobacterium motile by peritrichous flagella, designated strain OS-H1, was isolated from a sample of shoreline soil of the soda lake Ostozhe (pH 9.2, total salt content 0.22%) located in the steppe of south-east Siberia. In the first few transfers, the isolate produced heat-resistant endospores. Like other heliobacteria, strain OS-H1 contained bacteriochlorophyll g and lacked intracytoplasmic membranes. The new isolate was a strict anaerobe and photoheterotroph. In the light and in the presence of organic compounds, strain OS-H1 oxidized sulfide to elemental sulfur and polysulfides, but was not capable of photoautotrophic growth. The isolate was an obligate alkaliphile able to grow at pH 8-10.2. The best growth was observed at pH 8.5-9.5, a temperature of 30 degrees C and at 5-10 g sodium carbonate l(-1). Biotin was required as a growth factor. The G+C content of strain OS-H1 was 45.0 mol%. Comparison of the 16S rRNA gene sequence to that of phototrophic bacteria showed strain OS-H1 to group within gram-positive bacteria of the family Heliobacteriaceae with the closest relationship to Heliorestis daurensis (95.6% similarity). Based on physiological, genetic and chemotaxonomic characteristics, the new heliobacterium is described as a new species of the genus Heliorestis, Heliorestis baculata.

The Genome of Heliobacterium modesticaldum , a Phototrophic Representative of the Firmicutes Containing the Simplest Photosynthetic Apparatus

“…Genomic analyses of H. modesticaldum supported the restricted capacity for organic carbon photoassimilation previously observed in physiological studies (23). Although photoheterotrophic growth using fatty acids, such as butyrate and propionate, has been observed for some species of heliobacteria (4,6,9,43), H. modesticaldum is limited to photoassimilation of pyruvate, lactate, or acetate (23). Growth of Heliobacterium gestii, but not growth of H. modesticaldum, is supported by ethanol plus CO 2 (43).…”

Taxonomy, phylogeny, and ecology of the heliobacteria

“…convoluta, and Hrs. daurensis, all of which have been isolated from soda lakes and exhibit alkaline pH growth optima (pH 8-9) (Bryantseva et al 1999(Bryantseva et al , 2000aAsao et al 2006). The cells of Hrs.…”

Amino acid-assimilating phototrophic heliobacteria from soda lake environments: Heliorestis acidaminivorans sp. nov. and ‘Candidatus Heliomonas lunata’

“…nov. Strain SLH, although alkaliphilic, shows a novel phylogeny that places it outside of the Heliorestis clade. Moreover, because its 16S rRNA gene sequence is quite divergent Data were obtained from this study and from Bryantseva et al (1999Bryantseva et al ( , 2000b, Asao et al (2006), and Asao and Madigan (2010) Heliorestis acidaminivorans; aÁcidÁaÁminÁíÁvor'Áans; N.L. fem.…”

“…Species of Heliorestis include Heliorestis daurensis (Bryantseva et al 1999), Heliorestis baculata (Bryantseva et al 2000b), and Heliorestis convoluta (Asao et al 2006). All of these organisms were isolated from shoreline sediments/soils of soda lakes.…”