Complete Degradation of Hexahydro‐1,3,5‐Trinitro‐1,3,5‐Triazine (RDX) by a Co‐Culture of Gordonia sp. KTR9 and Methylobacterium sp. JS178

The presence of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in soil and groundwater is a major contamination issue at many military facilities around the world. Gordonia sp. KTR9 metabolizes RDX as a nitrogen source for growth producing 4-nitro-2,4-diazabutanal (NDAB) as a dead-end product. Methylobacterium sp. strain JS178 degrades NDAB as a sole source of nitrogen for growth. A mixed culture of strains KTR9 and JS178 was able to completely degrade RDX. There was no difference in rate of RDX degradation by KTR9 alone or in co-culture with JS178. The first-order degradation coefficients of RDX and NDAB in the co-culture were 0.08 hr−1 and 0.002 hr−1, respectively. In the co-culture that initially contained RDX plus NDAB, strain JS178 degraded the NDAB that was produced by KTR9 as shown by a decrease in the molar yield of NDAB (from RDX) from 1.0 to –0.11. Co-cultures of strains KTR9 and JS178 could be used to promote complete degradation of RDX in soils or groundwater. ©2016 Wiley Periodicals, Inc.