Rhodospirillales
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Rhodospirillales | ||||||||||
Pfennig & Trüper 1971 | ||||||||||
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The Rhodospirillales form an order within the Alphaproteobacteria . They consist of the families Rhodospirillaceae and Acetobacteraceae . The ecology, morphology and metabolism of bacteria of this order are very diverse. Here are chemotrophic , photoheterotrophe also photoautotrope and chemolithotrophic summarized bacteria because of 16S rRNA analysis. Many Rhodospirillales have a typical, corkscrew-like twisted cell morphology. They are mainly found in bodies of water and sediments.
Rhodospirillaceae
The species of this family, which belong to the non-sulfur purple bacteria , are for the most part photoheterotrophic, ie they need organic substances as electron donors . Your photosynthesis is anoxygenic, so it does not release oxygen. The species live anaerobically or tolerate microaerobic conditions. When there is no light, the bacteria grow chemotrophically . Species that are not capable of photosynthesis grow in an obligate chemoorganotroph (e.g. Azospirillum and Skermanella ). Many bacteria in this family are polar flagellated.
Among the Rhodospirillaceae there are some species that form intracellular magnetite crystals and arrange them in chains along the cell axis. This is how the movement of the cells is aligned along the earth's magnetic field ( magnetotaxis ). Examples of magnetotactic species are Magnetospirillum gryphiswaldense , Magnetospirillum magnetotacticum and Magnetospirillum magneticum . Magnetite crystal formation is a complex, not yet understood process that is genetically controlled and is currently being intensively researched as a special form of biomineralization .
Other genera: Phaeospirillum , Rhodospira , Rhodovibrio , Telmatospirillum , Rhodospira and Skermanella .
Acetobacteraceae
In contrast to the Rhodospirillaceae, this family, also known as acetic acid bacteria, includes mainly aerobic types of bacteria that do not perform photosynthesis, they need organic carbon sources for nutrition (chemoorganotroph) and they oxidize ethanol to acetic acid . Due to genetic studies, the systematics of this family at the genus level has recently been subject to some changes. For example, many species of the genus Acetobacter were placed under the genus Gluconacetobacter .
Other representatives of this family: Acidicaldus , Acidiphilium , Asaia , Granulibacter , Kozakia , Stella and Teichococcus .
literature
- George M. Garrity (Ed.): Bergey's Manual of Systematic Bacteriology . 2nd edition, Volume 2: The Proteobacteria. Part C: The Alpha-, Beta-, Delta-, and Epsilonproteabacteria. Springer, New York 2005, ISBN 0-387-24145-0 .