A Microbial Biorealm page on the genus Paraburkholderia
Higher order taxa
Domain; Phylum; Class; Order; family [Others may be used. Use NCBI link to find]
Description and significance
Paraburkholderia are largely known for their ability to degrade aromatic compounds and many hydrocarbons. Recent phylogenomic evidence has divided Paraburkholderia from Burkholderia (1). Some species of this genera have the ability to form root nodules that fix atmospheric nitrogen. The metabolic capabilities of Paraburkholderia has created notable interests in the biodegradation field, where the ability of these species of bacteria to break down pollutants in soil (1). There is special focus on the breakdown of PAHs, or organic pollutants known as polycyclic aromatic hydrocarbons created from pollution.
There are currently around 50-60 available genomes for Paraburkholderia. Diverse metabolic activity stems from its rather large genome of 7-10 Mb. Common G+C content of many Paraburkholderia species is 60-62% (2). Genomic DNA from strain RP11T was a strain of interest and sequenced at the Cornell University Sequencing Facility. The DNA sequencing of each strain of this bacteria proved to show advantages of metabolic decomposition of aromatic compounds. RP11T had different genomic factors from its close relatives, as it encoded the greatest number of genes in RAST (Rapid Annotations using Subsystem Technologies) for the metabolism of aromatics along with a great number of oxidases for aromatic-degradation (1). Additionally, a high number of encoded oxidizing enzymes were recognized in some strains, where all Paraburkholderia encode for the capability to grow on 4-hydroxybenzoic acid.
Cell structure and metabolism
Paraburkholderia madseniana is a Gram-negative bacteria, motile, and non-sporulating rods of about 0.8 µm by 1.4 µm. This species is often seen as diplobacillus (2). Paraburkholderia has vast metabolic activities and can be described as: facultative anaerobes, facultative chemolithotrophs, acid-tolerant and alkalizing, metal-tolerant, mineral weathering and phosphate solubilizing, polyaromatic hydrocarbon and xenobiotic degrading, plant-growth promoting, and nitrogen-fixing (1). In large, the metabolic activity of major significance is the role of plant-derived aromatic decomposition based on evidence of degradation of tannins and phenolics. Soil isolates have shown the ability to degrade PAH and halogenated phenols which indicates a diverse role in aromatic soil degradation as a whole. Paraburkholderia have been indicated as a strong contributor to affect the decomposition rate in soil where it is present due to this vast metabolic activity seen by its isolates.
There are currently 64 type strains of Paraburkholderia. The vast majority of strains originate from soils and plant roots with few strains described in aquatic environments. This genus is frequently isolated from acidic soils of forest and bogs, and particularly isolated from wood colonized by lignin-degrading white-rot fungi. Paraburkholderia is an environmental bacteria that lives in close proximity to plant and fungal tissues (3). These species produce a variety of metabolites with antimicrobial properties which allow them to suppress plant disease while killing many microbial pathogens. Additionally metabolic evidence of nitrogen fixation suggests that Paraburkholderia support plant growth. The bacteria use the plant and fungal tissues as a carbon source as explained by its metabolic activity of plant-derived aromatic degradation, and further indicate an efficient symbiotic relationship between the bacteria and organisms around it.
Application to Biotechnology
P. madseniana has significant biotechnological potential in its particular ability to degrade polycyclic aromatic hydrocarbons (PAHs) produced by burning fossil fuels. The increased interest in this genera of bacteria is the ability to use natural occurring bacteria derived from acidic soils to break down toxic pollutants.
Enter summaries of the most recent research here--at least three required
[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.
Edited by student of Dr. Charlotte Berkes