Halothiobacillaceae

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Halothiobacillaceae
Systematics
Domain : Bacteria (bacteria)
Department : Proteobacteria
Class : Gammaproteobacteria
Order : Chromatiales
Family : Halothiobacillaceae
Scientific name
Halothiobacillaceae
( Kelly & Wood 2005)

The Halothiobacillaceae form a family within the Gammaproteobacteria . The individual species belong to the so-called sulfur bacteria and gain energy through the oxidation of reduced sulfur compounds. The representatives are obligatorily aerobic and, like all proteobacteria, gram negative . The family consists of the two genera Halothiobacillus and Thiovirga . The genus Halothiobacillus and thus also the family Halothiobacillaceae was created in 2000 by converting different species of Thiobacillus (family Hydrogenophilaceae of the beta-proteobacteria ).

Metabolism and characteristics

The representatives of the Halothiobacillaceae are rod-shaped and can move with the help of flagella . They appear singly or in pairs.

The species can oxidize elemental sulfur , hydrogen sulfide (H 2 S), sulfides and thiosulfate (S 2 O 3 2− ), the genus Halothiobacillus also tetrathionate . The end product of the oxidation is sulfate. CO 2 is the only carbon source and is fixed for further use by the Calvin cycle . Since the different species are not able to use organic substances as a source of energy or carbon, they are obligate chemolithoautotroph . Carboxysomes are contained in the cells . They are surrounded by a protein shell. The enzyme ribulose-1,5-diphosphate carboxylase (RubisCO) is present in these small, polyhedral organelles . The CO 2 is transported into the carboxysomes by the enzyme carbonic anhydrase and thus delivered to RubisCO. The carboxysomes also prevent O 2 from being absorbed by RubisCO and thus photorespiration takes place. Carboxysomes are also present in many cyanobacteria .

Species of the Halothiobacillaceae are not able to use photosynthesis, this distinguishes them from the closely related families Chromatiaceae and Ectothiorhodospiraceae, which are in the same order. These two families form the physiological group of purple sulfur bacteria and also oxidize sulfur compounds, but always carry out anoxygenic photosynthesis. Anoxygen means that no oxygen is released. Here, hydrogen sulfide (H 2 S) or sulfide ions (S 2− ) serve as an electron donor for the reduction of CO 2 instead of water (H 2 O) . Thus, elemental sulfur (S) and no oxygen is released during this anoxygenic photosynthesis.

Systematics

The following is a list of some genera and species belonging to the Halothiobacillaceae family:

swell

  1. ↑ JP Euzéby: List of Prokaryotic names with Standing in Nomenclature - In: List of Prokaryotic names with Standing in Nomenclature (LPSN). Accessed April 27, 2019 :

literature

  • Michael T. Madigan, John M. Martinko, Jack Parker: Brock - Microbiology . 11th edition. Pearson Studium, Munich 2006, ISBN 3-8274-0566-1 .
  • DP Kelly and AP Wood: Reclassification of some species of Thiobacillus to the newly designated genera Acidithiobacillus gen. Nov., Halothiobacillus gen. Nov. and Thermithiobacillus gen. nov. In: International Journal of Systematic and Evolutionary Microbiology (2000) 50: pp. 489-500.
  • Tsukasa Ito, Kenichi Sugita, Isao Yumoto, Yoshinobu Nodasaka and Satoshi Okabe: Thiovirga sulfuroxydans gen. Nov., Sp. nov., a chemolithoautotrophic sulfur-oxidizing bacterium isolated from a microaerobic waste-water biofilm In: International Journal of Systematic and Evolutionary Microbiology (2005) 55: pp. 1059-1064