Microbial Degradation of Agent Orange and Mustard Related Compounds

Harvey, Steven P.; DeFrank, Joseph; Kamely, Daphne; Valdés, James J.; Chakrabarty, Ananda M.

doi:10.1007/978-94-011-3456-9_15

Cited by 3 publications

(2 citation statements)

References 8 publications

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“…Further investigations on surfactant production and secretion, emulsion formation and stabilization, and uptake of emulsified hydrocarbons are needed to elucidate the complex behavior of growth on water-insoluble compounds. The first results of remediation work in the enhanced removal of spilled oil from Alaskan gravel show some of the promising applications of P. aeruginosa surfactants (13).…”

Section: Discussionmentioning

confidence: 99%

Hydrocarbon assimilation and biosurfactant production in Pseudomonas aeruginosa mutants

Koch¹,

Käppeli²,

Fiechter³

et al. 1991

J Bacteriol

289

178

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We isolated transposon TnS-GM-induced mutants of Pseudomonas aeruginosa PG201 that were unable to grow in minimal media containing hexadecane as a carbon source. Some of these mutants lacked extracellular rhamnolipids, as shown by measuring the surface and interfacial tensions of the cell culture supernatants. Furthermore, the concentrated culture media of the mutant strains were tested for the presence of rhamnolipids by thin-layer chromatography and for rhamnolipid activities, including hemolysis and growth inhibition ofBacilus subtilis. Many procaryotic and eucaryotic microorganisms satisfy their carbon and energy requirements by using compounds, such as hydrocarbons, that are poorly soluble in aqueous media. The growth on hydrocarbons is often associated with the production of surface-active compounds. Surface-active molecules contain hydrophilic and hydrophobic components, a property that enables such molecules to concentrate at interfaces and to reduce the surface tensions of aqueous media. Several different microbial products that exhibit surface-active properties have been identified in the past. These so-called biosurfactants are produced by certain bacteria and by a number of yeasts and filamentous fungi. They include low-molecular-weight glycolipids, lipopeptides, and high-molecular-weight lipid-containing polymers such as lipoproteins, lipopolysaccharide-protein complexes, and polysaccharide-protein-fatty acid complexes. The common hydrophobic (lipophilic) moiety in biosurfactants is the hydrocarbon chain of a fatty acid, whereas the polar or hydrophilic group is derived from the ester or alcohol functional groups of neutral lipids, from the carboxylate group of fatty acids or amino acids, or, in the case of glycolipids, from carbohydrates. When the surfactants are extracellular, they cause the emulsification of the hydrocarbon. When they are cell wall associated, they facilitate the penetration of hydrocarbons to the periplasmic space. Many of the biosurfactants known today have been investigated with a view toward possible technical applications. Because biosurfactants are readily biodegradable and can be produced in large amounts by microorganisms and thus are not dependent on petroleum-derived products, they might well be able to replace, in some instances, the traditional synthetic surfactants. The structures, properties, and production of biosurfactants have been reviewed extensively; the overview of Reiser et al. (34) is the most recent. * Corresponding author.The rhamnose-containing glycolipids produced by Pseudomonas spp. (20,22,38) are among the biosurfactants to be studied most intensively. The rhamnolipids from Pseudomonas aeruginosa were first described in 1949 (24), and studies on the biosynthesis of these compounds were carried out in vivo by , who showed that these glycolipids were secreted into the medium during the stationary phase of growth. They also defined the optimal conditions for rhamnolipid production by this organism from various radioactive precursors, such as acetate, gly...

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Section: Discussionmentioning

confidence: 99%

Hydrocarbon assimilation and biosurfactant production in Pseudomonas aeruginosa mutants

Koch¹,

Käppeli²,

Fiechter³

et al. 1991

J Bacteriol

289

178

View full text Add to dashboard Cite

show abstract

“…115 For example, seminal work that focused on the development of genetically engineered bacterial Pseudomonas strains, encoding genes for the degradation of petroleum hydrocarbons such as camphor, octane, xylene, naphthalene, and salicylate, opened new pathways for the microbial biodegradation of organic pollutants. [116][117][118][119] Since then, technologies for the removal of pollutants have focused on the design and evolution of microbial and cell plant-assisted bioremediation pathways. 107,116,120 Materials that encapsulate microorganisms for bioremediation have demonstrated promising results in the sensing, monitoring, and treatment of environmental pollutants.…”

Section: Environmental Monitoringmentioning

confidence: 99%