Beijerinckia derxii

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Beijerinckia derxii

Classification

Higher order taxa

Bacteria; Proteobacteria; Alphaproteobacteria; Rhizobiales; Beijerinckiaceae; Beijerinckia; Beijerinckia derxii


NCBI: Taxonomy |}

Description and significance

Non-motile, unicellular organism. Free-living (non-symbiotic), Aerobic, chemoheterotrophic bacteria with N2 fixing capabilities. Rod-shaped when young; pear, or dumbbell shaped cells with aging; polar lipoid bodies on each end of the cell. These bacteria are extremely acid tolerant and have been shown to fix more nitrogen as the acidity levels increase (up to 2.7 pH) (Barbosa et. all. 2002)
It has been shown that within the Rhizosphere of rice plants, Beijerinckia numbers increase. No evaluation has yet been made to this phenomenon. Similar occurrences have been reported in sugar cane soils. One experiment demonstrated that sorghum strongly stimulates the growth of Beijerinckia.

Genome structure

Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence?


Cell structure and metabolism

Interesting features of cell structure; how it gains energy; what important molecules it produces.
The cell is rod-shaped, and does not have the ability to move. They generally range from 1.7-4.5μm in length and about .5-1.5 μm in diameter. Beijerinckia derxii is generally smaller than Azotobacter. They contain two lipoid structures at the polar ends of the cell. These structures are highly refractile and may be involved with light protection. It has the ability to turn a liquid media viscous by polysaccharide slime production. On surface media they produce raised colonies of highly elastic slime in varying colors. B. derxii can be characterized by a green fluorescent pigment.

Ecology

Initially isolated from a Malaysian quartzite soil by Altson in 1936 It can withstand very acidic conditions. This microbe has also been isolated from Europe, South America, Continental Asia, China, Japan, Australia, and Pacific Northwest Soils in the Americas. Suggesting that the microbe has world-wide distribution. It has been shown to resist freezing and the strands are viable indefinitely when frozen in liquid nitrogen. No reduction of viability occurs when stored for 3-4 months at -4° C. (Becking, 1961)

References

Becking J.H. Nitrogen Fixing bacteria of the genus Beijerinckia. Soil Science 118. p196-212.


Christina Kennedy. Genus I. Beijerinckia Derx

Heloiza R. Barbosa; Marcos A Moretti; Daniela S. Thuler; Elisabeth F.P. Augusto. Nitrogenase activity of Beijerinckia Derxii is preserved under adverse conditions for its growth. Brazilian Journal of Microbiology. São Paulo. Vol.33 no.3. July/Sept. 2002

Heloiza R. Barbosa; Deliela S. Thuler; Márcia A. Shirakawa; Natália R.S. Miyasaka. Beijerinckia Derxii stimulates the viability of non-n2-fixing bacteria in nitrogen-free media. Brazilian Journal of Microbiology. São Paulo. Vol.31 no3. July/Sept 2000

Jan Hendrik Becking. The Genus Beijerinckia. Prokaryotes 5. p151-162. 2006