Abstract
Hexanitrohexaazaisowurtzitane (CL-20) is a compound with a polycyclic cage and an N-nitro group that has been shown to play an unfavorable role in environmental fate, biosafety, and physical health. The aim of this study was to isolate the microbial community and to identify a single microbial strain that can degrade CL-20 with desirable efficiency. Metagenomic sequencing methods were performed to investigate the dynamic changes in the composition of the community diversity. The most varied genus among the microbial community was Pseudomonas, which increased from 1.46% to 44.63% during the period of incubation (MC0–MC4). Furthermore, the new strain was isolated and identified from the activated sludge by bacterial morphological and 16s rRNA sequencing analyses. The CL-20 concentrations decreased by 75.21 μg/mL and 74.02 μg/mL in 48 h by MC4 and Pseudomonas sp. ZyL-01, respectively. Moreover, ZyL-01 could decompose 98% CL-20 of the real effluent in 14 day’s incubation with the glucose as carbon source. Finally, a draft genome sequence was obtained to predict possible degrading enzymes involved in the biodegradation of CL-20. Specifically, 330 genes that are involved in energy production and conversion were annotated by Gene Ontology functional enrichment analysis, and some of these candidates may encode enzymes that are responsible for CL-20 degradation. In summary, our studies indicate that microbes might be a valuable biological resource for the treatment of environmental contamination caused by CL-20 and that Pseudomonas sp. ZyL-01 might be a promising candidate for eradicating CL-20 to achieve a more biosafe environment and improve public health.
Highlights
Hexanitrohexaazaisowurtzitane (HNIW or CL-20), with the formula C 6H6N12O12, is a nitroamine explosive that was first synthesized in 1987 (Nielsen et al 1989)
330 genes that are involved in energy production and conversion were annotated by Gene Ontology functional enrichment analysis, and some of these candidates may encode enzymes that are responsible for CL-20 degradation
It has been shown that extremely low concentrations of CL-20 in the soil even lead to a reduction in the density of earthworms (Eisenia fetida), suggesting that CL-20 appears to be more toxic to earthworms than TNT, RDX, and HMX (Panikov et al 2007)
Summary
Hexanitrohexaazaisowurtzitane (HNIW or CL-20), with the formula C 6H6N12O12, is a nitroamine explosive that was first synthesized in 1987 (Nielsen et al 1989). It has been shown that extremely low concentrations of CL-20 in the soil even lead to a reduction in the density of earthworms (Eisenia fetida), suggesting that CL-20 appears to be more toxic to earthworms than TNT, RDX, and HMX (Panikov et al 2007). Another study indicates that earthworm physiologies show clear retardation, stiffness, and body shrinkage after exposure to a low concentration of 0.02 μg/cm CL-20 compared with a high concentration of 0.21 μg/cm RDX (Gong et al 2007). Another study has shown that CL-20 has toxic effects in pregnant mice by teratogenic testing; simultaneously, it has been demonstrated that CL-20 possibly causes chromosomal damage and aneuploidy formation by increasing the micronucleus rate (Wenxia et al 2007). An effective and environmentally-friendly strategy is required to decontaminate environments due to an increasing awareness of the potential harmful effects caused by CL-20
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
