Designing bacterial consortia for the complete biodegradation of insensitive munitions compounds in waste streams. Issue 9 (27th June 2022)

• Record Type: Journal Article
• Authors: Menezes, Osmar; Owens, Cameron; Rios‐Valenciana, Erika E.; Sierra‐Alvarez, Reyes; Field, Jim A.; Spain, Jim C.
• Is Part Of: Biotechnology and bioengineering. Volume 119:Issue 9(2022)
• Page Start: 2437
• Page End: 2446
• Publication Date: 2022-06-27
• Subjects: insensitive high explosive -- nitroaromatic -- 2, 4‐dinitroanisole -- 3‐nitro‐1, 2, 4‐triazol‐5‐one -- 4‐chloronitrobenzene -- 4‐nitroanisole; Biotechnology -- Periodicals; Bioengineering -- Periodicals; 660.6
• DOI: 10.1002/bit.28160
• Languages: English
• ISSNs: 0006-3592

Abstract

Abstract: Insensitive munitions compounds (IMCs), such as 2, 4‐dinitroanisole (DNAN) and 3‐nitro‐1, 2, 4‐triazol‐5‐one (NTO), are replacing conventional explosives in munitions formulations. Manufacture and use of IMCs generate waste streams in manufacturing plants and load/assemble/pack facilities. There is a lack of practical experience in executing biodegradation strategies to treat IMCs waste streams. This study establishes a proof‐of‐concept that bacterial consortia can be designed to mineralize IMCs and co‐occurring nitroaromatics in waste streams. First, DNAN, 4‐nitroanisole (4‐NA), and 4‐chloronitrobenzene (4‐CNB) in a synthetic DNAN‐manufacturing waste stream were biodegraded using an aerobic fluidized‐bed reactor (FBR) inoculated with Nocardioides sp. JS 1661 (DNAN degrader), Rhodococcus sp. JS 3073 (4‐NA degrader), and Comamonadaceae sp. LW1 (4‐CNB degrader). No biodegradation was detected when the FBR was operated under anoxic conditions. Second, DNAN and NTO were biodegraded in a synthetic load/assemble/pack waste stream during a sequential treatment comprising: (i) aerobic DNAN biodegradation in the FBR; (ii) anaerobic NTO biotransformation to 3‐amino‐1, 2, 4‐triazol‐5‐one (ATO) by an NTO‐respiring enrichment; and (iii) aerobic ATO mineralization by an ATO‐oxidizing enrichment. Complete biodegradation relied on switching redox conditions. The results provide the basis for designing consortia to treat mixtures of IMCs and related waste products by incorporating microbes with the required catabolic capabilities. Abstract : This study demonstrates that bacterial consortia can be designed to mineralize insensitive munitions compounds and co‐occurring nitroaromatics in waste streams. Different cultures were combined either in an aerobic fluidized‐bed reactor to treat a synthetic 2, 4‐dinitroanisole‐manufacturing waste stream or in a sequential aerobic–anaerobic–aerobic process to treat a synthetic load/assemble/pack waste stream.