Bioremediation of Explosive TNT by <i>Trichoderma viride</i>

Abstract

Nitroaromatic and nitroamine compounds such as 2,4,6-trinitrotoluene (TNT) are teratogenic, cytotoxic, and may cause cellular mutations in humans, animals, plants, and microorganisms. Microbial-based bioremediation technologies have been shown to offer several advantages against the cellular toxicity of nitro-organic compounds. Thus, the current study was designed to evaluate the ability of Trichoderma viride to degrade nitrogenous explosives, such as TNT, by microbiological assay and Gas chromatography−mass spectrometry (GC−MS) analysis. In this study, T. viride fungus was shown to have the ability to decompose, and TNT explosives were used at doses of 50 and 100 ppm on the respective growth media as a nitrogenous source needed for normal growth. The GC/MS analysis confirmed the biodegradable efficiency of TNT, whereas the initial retention peak of the TNT compounds disappeared, and another two peaks appeared at the retention times of 9.31 and 13.14 min. Mass spectrum analysis identified 5-(hydroxymethyl)-2-furancarboxaldehyde with the molecular formula C6H6O3 and a molecular weight of 126 g·mol−1 as the major compound, and 4-propyl benzaldehyde with a formula of C10H12O and a molecular weight of 148 g mol−1 as the minor compound, both resulting from the biodegradation of TNT by T. viride. In conclusion, T. viride could be used in microbial-based bioremediation technologies as a biological agent to eradicate the toxicity of the TNT explosive. In addition, future molecular-based studies should be conducted to clearly identify the enzymes and the corresponding genes that give T. viride the ability to degrade and remediate TNT explosives. This could help in the eradication of soils contaminated with explosives or other toxic biohazards.

Keywords

• bioremediation
• explosives
• <i>trichoderma viride</i>
• gc/ms
• microbial screening