Acetobacterium woodii

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Classification

Domain: Bacteria

Phylum: Firmicutes

Class: Clostridia

Order: Clostridiales

Family: Eubacteriaceae

Species

NCBI: Taxonomy

Acetobacterium woodii

Isolated from black sediment of Oyster Pond inlet, Woods Hole, MA, USA. Named in honor of Harland G. Wood – An American Biochemist who pioneered studies which proved animals, humans, and bacteria use carbon dioxide in their metabolism. Wood studies proved that carbon dioxide can be used for the complete synthesis of acetate in bacteria.

Description and Significance

Acetobacterium woodii is an anaerobic gram-positive rod-shaped acetogenic bacterium. Uses one subterminal flagellum for motility, and in rare cases, has exhibited two flagella.

Oyster Pond, from which isolation of Acetobacterium woodii was achieved, has some a defining characteristic that sets it apart from most other habitats. Oyster pond started as an ocean inlet, with high salinity (~32 ppt). Gradually, storms caused a sandbar to form at the entrance to the inlet, which later was completely closed off from the ocean to make way for a set of train tracks. This caused the salinity levels to drop. Later, a weir was installed to regulate the pond's salinity between 2-4 ppt.

A. woodii has dependence on Na+ ions for metabolization of various substrates. Oyster pond's unique levels of salinity may provide an environment better suited for growth of A. woodii than normal freshwater (< 0.5 ppt) and saltwater (~35 ppt) bodies.

A. woodii produces acetate through homoacetogenic fermentation. The specificity of this microorganisms metabolism has potential industrial applications. Approximately 5 billion kg of acetic acid are produced annually in industry. A. woodii has the ability to provide sustainable production of these fuels and chemicals. While it mayUtilizing only H₂ gas and CO₂, A. woodii could be the solution to a more economical and even environmentally friendly solution to such a large industrial output.

Genome Structure

Describe the size and content of the genome. How many chromosomes? A. woodii has a circular DNA with 4,044,777 bp. The density and G+C content was studied using batches containing fructose and H₂-CO₂ medias. The buoyant density was determined to be 1.699 g/cm³ and the G+C content was 39 mol%. A. woodii has 2,889 proteins within its matrix and the average protein length is 330.5 amino acids. Other interesting features? What is known about its sequence?

Cell Structure, Metabolism and Life Cycle

Interesting features of cell structure; how it gains energy; what important molecules it produces.

Grows optimally at 30 degree C in 6 hours under a 80:20 mixture H₂-CO₂. With pH close to neutral (~6.8). H₂ serves as the electron donor and is oxidized while CO₂ serves as the electron acceptor and is reduced to form acetate 2 CO₂ + 4 H₂ -> CH₃COOH + 2 H₂O

This metabolic pathway is termed the Acetyl-CoA pathway. Also known as the Wood–Ljungdahl pathway, after the researchers who pieced together the process.

A. woodii can use other substrates than H₂ however the range of substrates is narrow and limited to fructose, glucose, lactate, glycerate, and formate. When the other substrates are used there a slight production of succinate was detected. The co-enzyme Pantothenate is required as a growth factor. Can also grow with CO as the sole energy source.

Ecology and Pathogenesis

Habitat; symbiosis; biogeochemical significance; contributions to environment.
If relevant, how does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.

Acetobacterium woodii may be present in ruminant animals and hindgut fermentation chambers of organisms. These hosts would benefit from the production of acetate which supplements their nutrition.

Acetogens dominate in many species of termites over methanogens. However, in other communities, methanogenic organisms out-compete acetogenic organisms for H₂ due to a higher threshold for hydrogen gas. In addition, some methanogens can metabolize acetate, the fermentive end-product of A. woodii.

Acetobacterium woodii is not pathogenic to humans. Although, "everything in moderation."

References

Acetate. 2014. [online] Wikipedia. Available at: <http://en.wikipedia.org/wiki/Acetate> [Accessed 20 Apr. 2014].

Acetobacterium woodii (strain ATCC 29683 / DSM 1030 / JCM 2381 / KCTC 1655). 2014. [online] Omabrowser.org. Available at: <http://omabrowser.org/cgi-bin/gateway.pl?f=DisplayOS&p1=ACEWD> [Accessed 20 Apr. 2014].

Balch, W. E., et al. (1977). Acetobacterium, a new genus of hydrogen-oxidizing, carbon dioxide-reducing, anaerobic bacteria. INTERNATIONAL JOURNAL OF SYSTEMATIC BACTERIOLOGY, 27(4), 355-361. Retrieved from http://ijs.sgmjournals.org/content/27/4/355.full.pdf

B R Sharak Genthner, M., 1987. Additional characteristics of one-carbon-compound utilization by Eubacterium limosum and Acetobacterium woodii. Applied and Environmental Microbiology, [online] 53(3), p.471. Available at: <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC203690/?page=1> [Accessed 20 Apr. 2014].

Eden, G. and Fuchs, G., 1983. Autotrophic CO2 fixation in Acetobacterium woodii. Archives of Microbiology, [online] 135(1), pp.68-73. Available at: <http://link.springer.com/article/10.1007%2FBF00419485#page-1> [Accessed 20 Apr. 2014].

Heise, R., et al. (1989). Sodium dependence of acetate formation by the acetogenic bacterium acetobacterium woodii. JOURNAL OF BACTERIOLOGY, 171(10), 5473-5478. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC210386/pdf/jbacter00176-0247.pdf

Kandler, O. and Schoberth, S., 1979. Murein structure of Acetobacterium woodii. Archives of Microbiology, [online] 120(2), pp.181-183. Available at: <http://link.springer.com/article/10.1007%2FBF00409106#page-1> [Accessed 20 Apr. 2014].

Kresge, N., Simoni, R. and Hill, R., 2005. The Discovery of Heterotrophic Carbon Dioxide Fixation by Harland G. Wood. Journal of Biological Chemistry, [online] 280(18), pp.e15-e15. Available at: <http://www.jbc.org/content/280/18/e15.full.pdf+html> [Accessed 20 Apr. 2014].

Oyster Pond Environmental Trust, Inc. 2014. [online] Opet.org. Available at: <http://www.opet.org/facts.html> [Accessed 20 Apr. 2014].

Poehlein, A., et al. (2011, July). Acetobacterium woodii (strain ATCC 29683 / DSM 1030 / JCM 2381 / KCTC 1655). Retrieved from http://hamap.expasy.org/proteomes/ACEWD.html

Straub, M., 2014. Selective enhancement of autotrophic acetate production with genetically modified Acetobacterium woodii. [online] Sciencedirect.com. Available at: <http://www.sciencedirect.com/science/article/pii/S0168165614001084> [Accessed 20 Apr. 2014].

Author

Page authored by Jacob Bryde and Tim Stieve, students of Drs. Kaz Kashefi and Edward Walker at Michigan State University.