Acetobacterium woodii
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 produced annually in industry. A. woodii has the ability to provide sustainable production of these fuels and chemicals. Utilizing only H2 gas and CO2, A. woodii could be the solution to a more economical and even environmentally friendly solution to an enormous output of acetic acid.
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. 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
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.
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. Examples of some animals that benefit from its presence are: cattle, goats, sheep, buffalo, termites, scarab beetles, cockroaches, and crickets. These hosts benefit from the production of acetate which supplements their nutrition.
Symbiosis with methanogens in rumen/hindgut? Acetogenesis dominate in many species of termites over methanogenesis. Methanogenic organisms compete with Acetogenic organisms for H2 in closed systems therefore Methanogens must be inhibited to determine growth of Acetogenic organisms and acetate production
Acetobacterium woodii is not pathogenic to humans.
References
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
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
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
Oyster Pond Environmental Trust, Inc. 2014. [online] Opet.org. Available at: <http://www.opet.org/facts.html> [Accessed 20 Apr. 2014].
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 _____, student of Prof. Jay Lennon at IndianaUniversity.