A rhamnolipid biosurfactant reduces cadmium toxicity during naphthalene biodegradation.
A model cocontaminated system was developed to determine whether a metal-complexing biosurfactant, rhamnolipid, could reduce metal toxicity to allow enhanced organic biodegradation by a Burkholderia sp. isolated from soil. Rhamnolipid eliminated cadmium toxicity when added at a 10-fold greater concentration than cadmium (890 microM), reduced toxicity when added at an equimolar concentration (89 microM), and had no effect at a 10-fold smaller concentration (8.9 microM). The mechanism by which rhamnolipid reduces metal toxicity may involve a combination of rhamnolipid complexation of cadmium and rhamnolipid interaction with the cell surface to alter cadmium uptake.
Sandrin
T R
TR
Department of Soil, Water, and Environmental Science, University of Arizona, Tucson, Arizona 85721, USA.
Chech
A M
AM
Maier
R M
RM
D001673:Biodegradation, Environmental; D019117:Burkholderia / Q000302:isolation & purification / Q000378:metabolism*; D002104:Cadmium / Q000494:pharmacology*; D003651:Decanoates / Q000494:pharmacology*; D009281:Naphthalenes / Q000378:metabolism*; D012210:Rhamnose / Q000031:analogs & derivatives* / Q000494:pharmacology*; D012988:Soil Microbiology; D013501:Surface-Active Agents / Q000494:pharmacology*
D003651:Decanoates; D009281:Naphthalenes; D013501:Surface-Active Agents; D002104:Cadmium; C031721:naphthalene; C085734:rhamnopyranosyl-3-hydroxydecanoyl-3-hydroxydecanoate; D012210:Rhamnose