Burkholderia xenovorans
Encyclopedia
Burkholderia xenovorans is a species of Proteobacteria
.
, non-catabolic physiological adaptation to organic compound
s, and the evolution of large bacterial genome
s. The metabolic pathway
s from phylogenetically diverse isolates are very similar with respect to overall organization. As originally noted in pseudomonads, a large number of "peripheral aromatic" pathways funnel a range of natural and xenobiotic
compounds into a restricted number of "central aromatic" pathways. These pathways are genetically organized in genus-specific fashions. Comparative genomic studies reveal that some pathways are more widespread than initially thought. Functional genomic studies have established that even organisms harboring high numbers of homologous enzymes seem to contain few examples of true redundancy. Analyses have indicated that recent genetic flux appears to have played a more significant role in the evolution of some large genomes, such as Burkholderia xenovorans LB400's, than others. However, the emerging trend is that the large gene repertoires of potent pollutant degraders such as Burkholderia xenovorans LB400 have evolved principally through more ancient processes. That this is true in such phylogenetically diverse species is remarkable and further suggests the ancient origin of this catabolic capacity. Aromatic compounds are among the most recalcitrant of organic pollutants and there is much interest in using Microbial biodegradation
to clean up contaminated sites.
of pollutant
s has intensified in recent years as mankind strives to find sustainable ways to cleanup contaminated environments. These bioremediation
methods harness the naturally occurring, microbial catabolic diversity to degrade, transform or accumulate a huge range of compounds including hydrocarbon
s (e.g. oil), polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), pharmaceutical substances, radionuclide
s and metals. Burkholderia xenovorans is one of the organisms currently being studied for this purpose.
Proteobacteria
The Proteobacteria are a major group of bacteria. They include a wide variety of pathogens, such as Escherichia, Salmonella, Vibrio, Helicobacter, and many other notable genera....
.
Genomics
The genome of Burkholderia xenovorans (LB400) is one of the largest bacterial genomes completely sequenced to date. The recent genomic studies of this organism have helped expand our understanding of bacterial catabolismCatabolism
Catabolism is the set of metabolic pathways that break down molecules into smaller units and release energy. In catabolism, large molecules such as polysaccharides, lipids, nucleic acids and proteins are broken down into smaller units such as monosaccharides, fatty acids, nucleotides, and amino...
, non-catabolic physiological adaptation to organic compound
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
s, and the evolution of large bacterial genome
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
s. The metabolic pathway
Metabolic pathway
In biochemistry, metabolic pathways are series of chemical reactions occurring within a cell. In each pathway, a principal chemical is modified by a series of chemical reactions. Enzymes catalyze these reactions, and often require dietary minerals, vitamins, and other cofactors in order to function...
s from phylogenetically diverse isolates are very similar with respect to overall organization. As originally noted in pseudomonads, a large number of "peripheral aromatic" pathways funnel a range of natural and xenobiotic
Xenobiotic
A xenobiotic is a chemical which is found in an organism but which is not normally produced or expected to be present in it. It can also cover substances which are present in much higher concentrations than are usual...
compounds into a restricted number of "central aromatic" pathways. These pathways are genetically organized in genus-specific fashions. Comparative genomic studies reveal that some pathways are more widespread than initially thought. Functional genomic studies have established that even organisms harboring high numbers of homologous enzymes seem to contain few examples of true redundancy. Analyses have indicated that recent genetic flux appears to have played a more significant role in the evolution of some large genomes, such as Burkholderia xenovorans LB400's, than others. However, the emerging trend is that the large gene repertoires of potent pollutant degraders such as Burkholderia xenovorans LB400 have evolved principally through more ancient processes. That this is true in such phylogenetically diverse species is remarkable and further suggests the ancient origin of this catabolic capacity. Aromatic compounds are among the most recalcitrant of organic pollutants and there is much interest in using Microbial biodegradation
Microbial biodegradation
Interest in the microbial biodegradation of pollutants has intensified in recent years as humanity strives to find sustainable ways to clean up contaminated environments...
to clean up contaminated sites.
Bioremediation
Interest in the microbial biodegradationMicrobial biodegradation
Interest in the microbial biodegradation of pollutants has intensified in recent years as humanity strives to find sustainable ways to clean up contaminated environments...
of pollutant
Pollutant
A pollutant is a waste material that pollutes air, water or soil, and is the cause of pollution.Three factors determine the severity of a pollutant: its chemical nature, its concentration and its persistence. Some pollutants are biodegradable and therefore will not persist in the environment in the...
s has intensified in recent years as mankind strives to find sustainable ways to cleanup contaminated environments. These bioremediation
Bioremediation
Bioremediation is the use of microorganism metabolism to remove pollutants. Technologies can be generally classified as in situ or ex situ. In situ bioremediation involves treating the contaminated material at the site, while ex situ involves the removal of the contaminated material to be treated...
methods harness the naturally occurring, microbial catabolic diversity to degrade, transform or accumulate a huge range of compounds including hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....
s (e.g. oil), polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), pharmaceutical substances, radionuclide
Radionuclide
A radionuclide is an atom with an unstable nucleus, which is a nucleus characterized by excess energy available to be imparted either to a newly created radiation particle within the nucleus or to an atomic electron. The radionuclide, in this process, undergoes radioactive decay, and emits gamma...
s and metals. Burkholderia xenovorans is one of the organisms currently being studied for this purpose.