Due to the shortage of bacteria resources for bioremediation of TNT red water polluted soil, a 2,4-dinitrotoluene sulfonates degrading strain X2 was isolated from a commercial microbial consortium. Based on the
16S rDNA sequence analysis and the physicbiochemical characteristics, strain X2 was identified as Sphingobium
sp.. The growth experiments were carried out to optimize the growth condition of X2. The biodegradation
mechanisms of 2,4-DNT-3-SO3- and 2,4-DNT-5-SO3- by X2 and its biodegradation ability towards other niro-aromatic explosives were investigated. The results showed that the optimum growing conditions for X2 were 30oC,
pH=7 and 1% salinity. The removal efficiencies of 2,4-DNT-3-SO3- and 2,4-DNT-5-SO3- reached 100% after 12
and 3 days, respectively. Liquid chromatography-mass spectrometry analysis showed that the nitro groups in
dinitrotoluene sulfonates were transformed to amino groups. Sphingobium sp. X2 has broad-spectrum degradation
characteristics. It can degrade not only dinitrotoluene sulfonates, but also other nitroaromatic pollutants like 2,4,6-trinitrotoluene, dinitrotoluene and mononitrotoluene, providing possibilities for TNT red water bioremediation.