Biodegradation of the High Explosive Hexanitrohexaazaiso-wurtzitane (CL-20)

• Main Authors: Steve Nicolich, Mohammed Sidhoum, Wendy Balas, Pelin Karakaya, Agamemnon Koutsospyros, Christos Christodoulatos
• Format: Article
• Language: English
• Published: MDPI AG 2009-04-01
• Series: International Journal of Environmental Research and Public Health
• Subjects: Hexanitrohexaazaisowurtzitane; CL-20; biodegradation; activated sludge; Phanerochaete chrysosporium; logistic growth model; mineralization
• Online Access: http://www.mdpi.com/1660-4601/6/4/1371/

The aerobic biodegradability of the high explosive CL-20 by activated sludge and the white rot fungus Phanerochaete chrysosporium has been investigated. Although activated sludge is not effective in degrading CL-20 directly, it can mineralize the alkaline hydrolysis products. Phanerochaete chrysosporium degrades CL-20 in the presence of supplementary carbon and nitrogen sources. Biodegradation studies were conducted using various nutrient media under diverse conditions. Variables included the CL-20 concentration; levels of carbon (as glycerol) and ammonium sulfate and yeast extract as sources of nitrogen. Cultures that received CL-20 at the time of inoculation transformed CL-20 completely under all nutrient conditions studied. When CL-20 was added to pre-grown cultures, degradation was limited. The extent of mineralization was monitored by the 14CO2 time evolution; up to 51% mineralization was achieved when the fungus was incubated with [14C]-CL-20. The kinetics of CL-20 biodegradation by Phanerochaete chrysosporium follows the logistic kinetic growth model.