ISOLATION OF 3 HEXAHYDRO-1,3,5-TRINITRO-1,3,5-TRIAZINE-DEGRADING SPECIES OF THE FAMILY ENTEROBACTERIACEAE FROM NITRAMINE EXPLOSIVE-CONTAMINATED SOIL

Three species of the family Enterobacteriaceae that biochemically reduced hexahydro- 1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) were isolated from nitramine explosive-contaminated soil. Two isolates, identified as Morganella morganii and Providencin rettgeri, completely transformed both RDX and the nitroso-RDX reduction intermediates. The third isolate, identified as Citrobacter freundii, partially transformed RDX and generated high concentrations of nitroso-RDX intermediates. All three isolates produced (CO2)-C-14 from labeled RDX under O-2-depleted culture conditions. While all three isolates transformed HMX, only M. morganii transformed HMX in the presence of RDX.