Biodegradation of 2,4,6-trinitrotoluene by Biofilm Forming and Plant Growth Promoting Burkholderia gladioli: An Approach Towards Degradation Pathway Prediction
摘要
2,4,6-trinitrotoluene (TNT) is one of the munition waste that contaminates the army bases and explosive manufacturing units. In our current study, bacterial isolate VITAPMJ1 obtained from soil contaminated with explosive waste, was capable of resisting TNT upto the concentration of 250 mg L−1 along with biofilm formation. Further, biodegradation studies revealed the ability of VITAPMJ1 in degrading TNT through UPLC analysis, where, a significant reduction in the peak area indicated the degradation of TNT. Metabolomic analysis of the intermediates upon degradation was identified to be 4-Amino-2,6-dinitrotoluene (4-ADNT), 2-Amino-4, 6-Dinitrotoluene(2-ADNT), and 1,2-Dimethyl-3-nitro-4-nitroso-benzene which were further used for the prediction of TNT degradation pathway. The strain VITAPMJ1 was also found to be a Plant Growth Promoting Bacteria (PGPB) as it was capable of producing indole acetic acid, siderophore, ammonia and was able to solubilising insoluble phosphate. The molecular characterization by 16S rRNA gene sequencing revealed that the evolutionary distant matrix of VITAPMJ1 was closely associated with Burkholderia gladioli. There was an increase in the germination index of the seeds treated with bacterial degraded products which confirmed the less-toxic nature of the degraded products. The mechanism involved in the degradation was confirmed by the amplification of ntr gene which was responsible for degradation of TNT by Burkholderia gladioli.
Graphical Abstract