Oceanospirillum

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Oceanospirillum
Systematics
Domain : Bacteria (bacteria)
Department : Proteobacteria
Class : Gammaproteobacteria
Order : Oceanospirillales
Family : Oceanospirillaceae
Genre : Oceanospirillum
Scientific name
Oceanospirillum
Hylemon et al. 1973

Oceanospirillum is a genus of bacteria . The genus is Gram-negative and belongs to the Proteobacteria . The generic name is based on the Latin word "Oceanus" (ocean) and the Greek word "spira" (spiral) and indicates the place where the species live and the spiral cells .

Appearance

The cells of Oceanospirillum are spirally wound ( helical ). The turns of the helix are right-handed. At both poles there are tufts of flagella , so they are bipolar polytrich flagellated. So they resemble the spirochetes in appearance , but are phylogenetically far apart. The cell diameter is between 0.3 and 1.2 μm. Under the cytoplasmic membrane there is another membrane at the two polar ends. It is also called polar membrane in English . It is attached to the inside of the plasma membrane by rod-shaped connections and is most often located in the region around the polar flagella. Such a membrane has mainly been found in genera of helical bacteria such as Spirillum , Campylobacter , Aquaspirillum , Ectothiorhodospira and Rhodospirillum . Oceanospirillum , like some other rigid helical bacteria, can form cocoid cell bodies, also known as "microcysts" , in older cultures . This cell shape dominates in older cultures. These cells have thin cell walls and resemble spheroplasts such as those formed by Flavobacterium . The majority of the coconut cell bodies present in ancient cultures are viable and can "germinate" when placed in fresh medium. Germination occurs by unipolar or bipolar growth of a helical cell from the coccyx body, the latter being absorbed by the developing cell.

The colonies of Oceanospirillum usually develop within 2-3 days on marine agar (MA) and are usually white, circular, and convex. The species O. sanctuarii shows pale yellow colonies.

metabolism

Oceanospirillum is aerobic , so it needs oxygen. The metabolic pathway is breathing with oxygen as the terminal electron acceptor. Oceanospirillum is chemoorganotrophic . The optimal growth temperature is between 25 and 32 ° C, depending on the species. The oxidase test is positive. The indole test turns out negative. Casein , starch , hippurate and aesculin are not hydrolyzed by the types described in Bergey's Manual of Systematic Bacteriology , published in 2005 . The species Oceanospirillum sanctuarii , introduced in 2017 , also does not use casein, starch or aesculin; no information is given about hippurate in the first description of this species.

The species need lake water for growth. Poly-β-hydroxybutyric acid (PHB) is stored in the form of granules .

Systematics

The genus Oceanospirillum is part of the Oceanospirillaceae family , which belongs to the Proteobacteria division . The genus was established in 1973 by PB Hylemon. The type species is Oceanospirillum linum . The genus Oceanospirillum was originally established to distinguish the marine species of Spirillum from those found in freshwater. Thus the marine species Spirillum linum became the type species of the newly established genus Oceanospirillum .

The following is a list of species (as of April 2020):

Many species have been converted, for example the species Oceanospirillum pusillum is now added to the genus Terasakella as T. pusilla . Oceanospirillum vagum is now listed as Marinomonas vaga , Oceanospirillum commune as Marinomonas communis , O. minutulum as Marinospirillum minutulum , O. japonicum as Pseudospirillum japonicum . Oceanospirillum kriegii was assigned to the genus Oceanobacter .

ecology

Oceanospirillum needs salt water to grow. Species of Oceanospirillum have been isolated from coastal sea water and rotting seaweed, among other things. The species O. sanctuarii was found within a sample of sediments from a mangrove forest .

The species of Oceanospirillum found in the sea close to the coast include z. B. O. linum , O. maris and O. beijerinckii . It is not known whether species occur freely in the open sea (as of 2014). It has been suggested that Oceanospirilla's growth may be restricted to environments with higher concentrations of nutrients in seawater, such as near decomposing particles.

Individual evidence

  1. ↑ a b c d e f George M. Garrity: Bergey's manual of systematic bacteriology . 2nd Edition. Springer, New York, 2005, Vol. 2: The Proteobacteria Part C: The Alpha-, Beta-, Delta-, and Epsilonproteabacteria ISBN 0-387-24145-0
  2. ↑ a b c d Chandni Sidhu et al .: Oceanospirillum sanctuarii sp. nov., isolated from a sediment sample In: International Journal of Systematic and Evolutionary Microbiology (2017), 67, pp. 3428-3434. doi : 10.1099 / ijsem.0.002132
  3. ↑ PB Hylemon, JS Wells Jr., NR Krieg and HW Jannash: The Genus Spirillum: a Taxonomic Study In: International Journal of Systematic and Evolutionary Microbiology (1973), Vol. 23, Iss. 4, pp. 340-380. doi : 10.1099 / 00207713-23-4-340
  4. ↑ Genus Oceanospirillum (as of April 1, 2020).
  5. ^ A b c Eugene Rosenberg, Edward F. DeLong, Stephen Lory, Erko Stackebrandt , Fabiano Thompson: The Prokaryotes. Gammaproteobacteria. 4th edition, Springer, 2014, ISBN 3642389236
  6. ↑ Jannasch HW: Studies on the ecology of a marine spirillum in the chemostat In: 1st international symposium on marine microbiology. CC Thomas, Springfield, pp. 558-566

literature