Cyclodextrins in bioremediation of contaminated soil

Application of cyclodextrins (CDs) in environmental management has been recently reviewed (1,2). Due to the multiple benefits offered by these complex forming carbohydrates such as improving the solubility, decreasing the volatility, and changing the partition of the contaminants between the soil phases as well as enhancing the bioavailability (toxicity) of the contaminants these additives have been thoroughly studied in soil remediation technologies, that is in technologies cleaning the contaminated soil. Bioremediation is an innovative technology which uses microorganisms to degrade organic contaminants in soil either excavated or in situ (3). The microorganisms break down contaminants by using them as a nutrient or cometabolizing them with a nutrient. Aerobic processes require an oxygen source, and the end products typically are carbon dioxide and water. Anaerobic processes are conducted in the absence of oxygen, and the end products can include methane, hydrogen gas, sulfide, elemental sulfur, and dinitrogen gas. Both under aerobic and anaerobic conditions the bioavailability can be the rate limiting factor. In such cases, solubilization with CD complexation can help.