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MOLECULAR STUDIES OF PSEUDOMONAS AERUGINOSA CHL-004'S INTERACTION WITH HEAVY METALS
Citation:
FELDHAKE, D. AND W. J. DAVIS-HOOVER. MOLECULAR STUDIES OF PSEUDOMONAS AERUGINOSA CHL-004'S INTERACTION WITH HEAVY METALS. Presented at In Situ & On-Site Bioremediation 8th International Symposium, Baltimore, MD, June 06 - 09, 2005.
Impact/Purpose:
to present information
Description:
Heavy metal contamination of soils and sediments as the result of human activity is of worldwide concern. In particular lead, which has been used in the production of batteries, gasoline, paint and pigments, is a potent neurotoxin when taken internally. Ingestion of lead can result in heart problems, kidney damage, and mental retardation. Other heavy metals such as cadmium, mercury and arsenic have also been released into the environment as industrial waste products and pose significant health threats. The use of bacteria to concentrate or bioaccumulate heavy metals from contaminated soils is currently being investigated as a method for bioremediation. Pseudomonas aeruginosa CHL-004 is an environmental isolate which has been shown to concentrate lead from both liquid and solid media. In general, bacteria can accumulate heavy metals such as lead by sorption to exopolymers or other cell components, or bacteria can transport heavy metals and bioaccumulate them intracellularly. The bioaccumulation of lead by CHL-004 is unusual in that it sequesters lead intracellularly as a lead-phosphorus complex within discrete inclusion bodies. The mechanism for the transport and accumulation of lead by CHL004 is currently under investigation, as are CHL-004's interactions with cadmium, arsenic and mercury. DNA probes derived from sequences of heavy metal transport and resistance genes are being used to determine a) if the CHL-004 genome includes sequences with homology to genes associated with specific mechanisms of heavy metal transport and resistance and b) if relevant genes are chromosomal or located on plasmids. These results will be used in future work to clone genes and further characterize mechanisms of CHL-004's accumulation of lead and resistance to heavy metals.