摘要: |
The U.S. Army generates large volumes of explosives-contaminated wastewater during munitions production and demilitarization operations. Contaminants such as 2,4,6-trinitrotoluene (TNT) and hexahydro-l,3,5-trinitro-l, 3,5-triazine (RDX) are environmentally hazardous and must be removed from the wastewater. This research examined the transformation of TNT and RDX in cell extracts of Clostridium acetobutylicum. C. acetobutylicum was grown in thioglycollate medium at 37 C. Cells were harvested by centrifugation and frozen in 1-gram packets at-8O C for later use. Cells (100 mg) were placed in 30-ml serum bottles and incubated anoxically under an N2 headspace in phosphate buffer containing lysozyme. Following lysis, TNT was added to the lysed cells. Periodically the contents of the serum bottle were analyzed for TNT and the formation of TNT degradation intermediates. TNT was completely degraded in 60 minutes without observing any TNT reduction products in the cell extract supernatant. The addition of pyruvates to the serum bottles increased the TNT degradation rate 10-fold. RDX was completely degraded in l-g cell extracts after 60 minutes, but not in 100-mg cell extracts. No TNT degradation and <25 percent RDX degradation occurred in cell extracts incubated aerobically. These studies indicate that cell extracts of C. acetobutylicum are capable of degrading TNT and RDX. |