TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Bacterium: In (I), the growth medium that supports the growth of Methylobacterium sp. is Luria Bertani (LB) medium. (I) degrades a nitroaromatic or nitramine compound, a high energy compound such as 2,4,6-trinitrotoluene (TNT), royal demolition explosive; hexahydro-1,3,5-trinitro-1,3,5-triazene (RDX) and high melting point explosive; octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). The Poplar tissue comprises a tissue explant from a Poplar tree, preferably Populus deltoides nigra DN34. The Poplar tissue is from tissue culture or tissue from regenerated plantlet.Preferred Method: In (M1), the tissue from a Poplar tree is a surface-sterilized tissue explant, tissue grown in tissue culture, or a regenerated plantlet. The growth medium comprises LB, nutrient agar (NA) or modified Jayasuriya's medium.Preferred Composition: In (II), the Methylobacterium sp. is present at a density of 109 cells/ml or greater. (II) has a pH of 3.0-11.0, preferably 6.0-8.0, a temperature of 4-41 degrees C, preferably 15-37 degrees C and an oxygen saturation of 5-100 %, preferably 20-100 %.Preferred Preparation: (III) has a cell concentration of 1-95 % by volume. (III) further comprises an additional microbial species, which is another member of the genus Methylobacterium, and one or more nutrients for the Methylobacterium. EXAMPLE - Cell suspensions of Methylobacterium sp. strain BJ001 in pure culture were exposed separately to nitro-substituted explosives 2,4,6-trinitrotoluene (TNT), royal demolition explosive; hexahydro-1,3,5-trinitro-1,3,5-triazene (RDX) and high melting point explosive; octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). Flasks were equipped with a CO2 trap consisting of a 5 ml glass vial containing 1 ml of 1.0 N NaOH. Each bioreactor contained 100 ml of liquid Luria Bertani (LB) medium supplemented with 14C(-U-ring)-TNT (25 mg L-1), 14C(-U-ring)-RDX (20 mg L-1), or 14C(-U-ring)-HMX (2.5 mg L-1). Each flask was inoculated with a concentrated cell suspension (1.0 % v/v). The inoculum was prepared from a 48 hours old log-phase cell suspension growing in LB medium supplemented with methanol (0.5% v/v) or fructose (0.5 % w/v) and incubated under stirring at 28 degrees C. Cells were harvested by centrifugation (30 minutes, 5000 rpm) and re-suspended in sterile deionized (DI) water. Bacteria were shown to fully transform the nitro-substituted explosives over the 55 days of experiment. While TNT disappeared completely in less than 10 days, no significant mineralization (that is release of 14CO2) or decrease of the radioactivity in solution was observed. In contrast, RDX and HMX concentrations decreased more slowly (reaching non-detectable levels after 40 days), but with a significant release of 14CO2.