Degradation of 2,4,6-trinitrotoluene by P. aeruginosa and characterization of some metabolites

Abstract

Degradation of 2,4,6-trinitrotoluene (TNT), a nitroaromatic explosive found in the soil and ground water, was investigated using Pseudomonas aeruginosa in in vitro experiments . Biodegradable abilitiy of this bacteria was performed with 50 and 75 mg L −1 TNT concentrations in a defined liquid medium for 96 h time period. Treatment of TNT in supernatant samples taken at 0, 6, 12, 24, 48, 72 and 96 h from agitated vessels was followed by reverse-phase high-performance liquid chromatography (HPLC). In cultures supplemented with 50 and 75 mgL −1 TNT, after 96 h of incubation 46% and 59% reduction were detected respectively. Two metabolites as degradation intermediates with nitrite release into the medium, 2,4-dinitrotoluene (2,4-DNT) and 4-aminodinitrotoluene (4-ADNT), were elucidated by thin layer chromatography (TLC) and gas chromatography-mass spectrometry (GC-MS). These findings clearly indicate that Pseudomonas aeruginosa can be used in bioremediation of TNT contaminated sites.

Bioremediation of Explosive TNT by Trichoderma viride

“…Thus, the extensive use of these explosives in military applications requires the implementation of extensive handling and disposal techniques, whereas their transformation products lead to increased environmental pollution-particularly in the soil, sediment, surface, and groundwater-to levels that threaten human health and the environment [12][13][14][15][16]. In addition, animal experimental studies have reported that the transformation products of TNT are teratogenic, cytotoxic, and may cause cell mutation; however, the carcinogenic effects of TNT on humans still need to be explored [17,18]. This may be related to the eco-toxicological effects and persistence of TNT and its transformation products in the environment, which significantly affects a wide range of ecological receptors, particularly microorganisms, algae, plants, invertebrates, some vertebrates, and humans [19][20][21].…”

“…These compounds have been shown to have a low biodegradability and higher persistence in the environment [2,3]. In addition, it was reported that the transformation products of TNT are teratogenic, cytotoxic, and may cause cell mutations in animal experimental models [17,18]. However, the carcinogenic effects of TNT on humans still need to be explored [17,18].…”

“…In addition, it was reported that the transformation products of TNT are teratogenic, cytotoxic, and may cause cell mutations in animal experimental models [17,18]. However, the carcinogenic effects of TNT on humans still need to be explored [17,18]. This may be related to the eco-toxicological effects and persistence of TNT and its transformation products in the environment, which significantly affect a wide range of ecological receptors, particularly microorganisms, algae, plants, invertebrates, some vertebrates, and humans [19][20][21].…”

Biodegradation of 2, 4, 6- Trinitrotoluene (TNT) in Contaminated Soil and Microbial Remediation Options for Treatment

“…Out of the 17,000 people poisoned by TNT, 3% of deaths were reported as a result of inhalation, ingestion or dermal sorption of TNT particulates [18]. Even though there is insufficient evidence of TNT carcinogenicity to humans, the United States Environmental Protection Agency (US EPA) has recently listed TNT as a likely cancer causing to human beings [18,19]. For the purposes of public health protection, some toxicity thresholds values have been set.…”

“…Other studies [17,18] conducted on animals such as dogs, mice, rats, and frogs indicated that TNT and its transformation products are teratogenic, cytotoxic and may cause cell mutation. However, the carcinogenic effects of TNT on humans still need to be explored [18,19]. Due to the ecotoxicological effects and persistence of TNT and its transformation products in the environment, the physico-chemical methods [2,20], and the bioremediation technologies [21][22][23][24] have been applied to remediate polluted environment by TNT.…”