TABLE 2.

Mineralization of [14C]RDX, [14C]HMX, and [14C]TNT by Methylobacterium sp. strain BJ001 after 20 days of exposurea

Substrate[14C]RDX (20 mg liter−1)[14C]HMX (2.5 mg liter−1)[14C]TNT (25 mg liter−1)Controls
14CO2 (%)Biomass (mg liter−1)14CO2 (%)Biomass (mg liter−1)14CO2 (%)Biomass (mg liter−1)
Minimal medium with:
    Fructose and NH4NO37.74 ± 0.331.03 ± 0.116.75 ± 0.661.02 ± 0.220.34 ± 0.130.97 ± 0.061.06 ± 0.08
    Fructose7.03 ± 0.910.74 ± 0.165.03 ± 0.321.07 ± 0.050.25 ± 0.170.97 ± 0.131.08 ± 0.14
    NH4NO30.08 ± 0.030.11 ± 0.020.12 ± 0.080.09 ± 0.040.21 ± 0.100.16 ± 0.080.11 ± 0.03
    No fructose and no NH4NO30.19 ± 0.150.14 ± 0.080.18 ± 0.140.16 ± 0.060.19 ± 0.130.19 ± 0.050.17 ± 0.05
Positive control18.08 ± 3.031.05 ± 0.0715.54 ± 1.81.08 ± 0.060.56 ± 0.071.06 ± 0.151.12 ± 0.07
Negative control0.35 ± 0.230.06 ± 0.020.11 ± 0.040.22 ± 0.240.35 ± 0.070.09 ± 0.060.09 ± 0.01
  • a Cells were grown on minimal medium supplemented with the following carbon and/or nitrogen sources: fructose (5.0 g liter−1) and NH4NO3 (1.2 g liter−1 [3.0 mM]), fructose only, NH4NO3 only, and no fructose and no NH4NO3. For each set of experiment, LB medium and noninoculated minimal medium were used as positive and negative control media, respectively. Control experiments consisted of the same set of media without addition of [14C]RDX, [14C]HMX, or [14C]TNT. Results are presented as means ± standard deviations.