Taxonomic Comments

Thiorhodovibrio winogradskyi was described based on two isolates that show significant phenotypic differences (Overmann et al., 1992). Both strains may be considered different species, and the description of Thiorhodovibrio winogradskyi given here is that of the type strain (DSM 6702, SSP1). The following properties distinguish strain 06511 from the type strain of Thiorhodovibrio wi-nogradskyi: Cells are spirilloid, 0.7-0.9 X 2.5-3.9 |im. Thiosulfate is used as photosynthetic electron donor and the mol% G + C content of the DNA is 62.4. Propionate does not support growth of strain 06511. However, in addition to the substrates used by the type strain, succinate, fumarate, malate, tartrate, malonate, glycerol, and peptone stimulate growth slightly (Overmann et al., 1992) for strain O6511.

Further Reading

Overmann, J., Fischer, U. and Pfennig, N. 1992. A new purple sulfur bacterium from saline littoral sediments, Thiorhodovibrio winogradsky gen. nov. and sp. nov. Arch. Microbiol. 157: 329-335.

List of species of the genus Thiorhodovibrio

1. Thiorhodovibrio winogradskyi Overmann, Fischer and Pfennig 1993, 188VP (Effective publication: Overmann, Fischer and Pfennig 1992, 334.)'sky.i. M.L. gen. n. winogradskyi of Winogradsky, named for S.N. Winogradsky, a Russian microbiologist, who did the first comprehensive studies on the purple sulfur bacteria.

Cells vibrioid, 1.2-1.6 X 2.6-4.0 |im, motile by a single polar flagellum. Gram negative and belong to the Gam-maproteobacteria. Anaerobically grown cultures pink to light pinkish purple. Living cell suspensions have absorption maxima at 370-372, 483-484, 510, 590-591, 794-795, and 867 nm. Photosynthetic pigments are bacteriochlorophyll a and carotenoids of the spirilloxanthin group, with rho-dopin as the major component, and spirilloxanthin, lyco-pene, anhydrorhodovibrin, and rhodovibrin.

Photolithoautotrophic growth with sulfide and S0 as pho-

tosynthetic electron donors. When growing on sulfide, up to ten small sulfur globules are formed inside the cell, often in a row along its long axis. High growth rates are obtained with S0 as electron donor. In the presence of sulfide and hydrogen carbonate, acetate, pyruvate, and propionate are photoassimilated. Chemotrophic growth possible under mixotrophic conditions at reduced oxygen partial pressure (~1% O2). No vitamins required.

Mesophilic marine bacterium requiring NaCl, with optimum growth at 2.2-3.2% NaCl (range 0.2-7.2% NaCl), pH 7.0-7.4 and 33°C (temperature range 14-37°C).

Habitat: sulfide-containing surface layers of salt lake sediments and marine microbial mats.

Type strain: SSP1, DSM 6702.

GenBank accession number (16SrRNA): AB016986, AJ006214, Y12368.

0 0

Post a comment