Improved TNT detoxification by starch addition in a nitrogen-fixing Methylophilus-dominant aerobic microbial consortium.
In this study, a novel aerobic microbial consortium for the complete detoxification of 2,4,6-trinitrotoluene (TNT) was developed using starch as a slow-releasing carbon source under nitrogen-fixing conditions. Aerobic TNT biodegradation coupled with microbial growth was effectively stimulated by the co-addition of starch and TNT under nitrogen-fixing conditions. The addition of starch with TNT led to TNT mineralization via ring cleavage without accumulation of any toxic by-products, indicating improved TNT detoxification by the co-addition of starch and TNT. Pyrosequencing targeting the bacterial 16S rRNA gene suggested that Methylophilus and Pseudoxanthomonas population were significantly stimulated by the co-addition of starch and TNT and that the Methylophilus population became predominant in the consortium. Together with our previous study regarding starch-stimulated RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) degradation (Khan et al., J. Hazard. Mater. 287 (2015) 243-251), this work suggests that the co-addition of starch with a target explosive is an effective way to stimulate aerobic explosive degradation under nitrogen-fixing conditions for enhancing explosive detoxification.
Department of Civil and Environmental Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea; Department of Agronomy, University of Agriculture, Faisalabad 38040, Pakistan.
Muhammad Imran
MI
Khan
Department of Civil and Environmental Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea.
Jaejin
J
Lee
Department of Civil and Environmental Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea.
Keunje
K
Yoo
Department of Civil and Environmental Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea.
Seonghoon
S
Kim
Department of Civil and Environmental Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea. Electronic address: parkj@yonsei.ac.kr.
Joonhong
J
Park
D000332:Aerobiosis; D004269:DNA, Bacterial / Q000032:analysis / Q000096:biosynthesis; D052918:Environmental Restoration and Remediation / Q000379:methods*; D053834:Explosive Agents / Q000737:chemistry*; D020629:Methylophilus / Q000187:drug effects / Q000378:metabolism*; D059013:Microbial Consortia; D009586:Nitrogen Fixation / Q000187:drug effects*; D012336:RNA, Ribosomal, 16S / Q000378:metabolism; D013213:Starch / Q000494:pharmacology*; D014303:Trinitrotoluene / Q000737:chemistry* / Q000378:metabolism
D004269:DNA, Bacterial; D053834:Explosive Agents; D012336:RNA, Ribosomal, 16S; D014303:Trinitrotoluene; D013213:Starch
Bioremediation; Explosives; Pyrosequencing; Starch