+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Isolation and characterization of RDX-degrading Rhodococcus species from a contaminated aquifer

Isolation and characterization of RDX-degrading Rhodococcus species from a contaminated aquifer

Biodegradation 22(5): 997-1005

Groundwater contamination by the explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a global problem. Israel's coastal aquifer was contaminated with RDX. This aquifer is mostly aerobic and we therefore sought aerobic bacteria that might be involved in natural attenuation of the compound in the aquifer. RDX-degrading bacteria were captured by passively sampling the indigenous bacteria onto sterile sediments placed within sampling boreholes. Aerobic RDX biodegradation potential was detected in the sediments sampled from different locations along the plume. RDX degradation with the native sampled consortium was accompanied by 4-nitro-2,4-diazabutanal formation. Two bacterial strains of the genus Rhodococcus were isolated from the sediments and identified as aerobic RDX degraders. The xplA gene encoding the cytochrome P450 enzyme was partially (~500 bp) sequenced from both isolates. The obtained DNA sequences had 99% identity with corresponding gene fragments of previously isolated RDX-degrading Rhodococcus strains. RDX degradation by both strains was prevented by 200 μM of the cytochrome P450 inhibitor metyrapone, suggesting that cytochrome P450 indeed mediates the initial step in RDX degradation. RDX biodegradation activity by the T7 isolate was inhibited in the presence of nitrate or ammonium concentrations above 1.6 and 5.5 mM, respectively (100 mg l(-1)) while the T9N isolate's activity was retarded only by ammonium concentrations above 5.5 mM. This study shows that bacteria from the genus Rhodococcus, potentially degrade RDX in the saturated zone as well, following the same aerobic degradation pathway defined for other Rhodococcus species. RDX-degrading activity by the Rhodococcus species isolate T9N may have important implications for the bioremediation of nitrate-rich RDX-contaminated aquifers.

Please choose payment method:

(PDF emailed within 0-6 h: $19.90)

Accession: 054011335

Download citation: RISBibTeXText

PMID: 21327803

DOI: 10.1007/s10532-011-9458-0

Related references

Isolation and characterization of an atrazine-degrading Rhodococcus sp. strain MB-P1 from contaminated soil. Letters in Applied Microbiology 49(6): 721-729, 2009

Isolation and characterization of dibenzofuran-degrading actinomycetes: analysis of multiple extradiol dioxygenase genes in dibenzofuran-degrading Rhodococcus species. Bioscience Biotechnology and Biochemistry 66(7): 1462-1472, 2002

Identification and characterization of o-xylene-degrading Rhodococcus spp. which were dominant species in the remediation of o-xylene-contaminated soils. Biodegradation 18(1): 17-26, 2007

Dioxygenases of Chlorobiphenyl-Degrading Species Rhodococcus wratislaviensis G10 and Chlorophenol-Degrading Species Rhodococcus opacus 1CP Induced in Benzoate-Grown Cells and Genes Potentially Involved in These Processes. Biochemistry. Biokhimiia 81(9): 986-998, 2016

Isolation of alkali-tolerant benzene-degrading bacteria from a contaminated aquifer. Letters in Applied Microbiology 47(1): 60-66, 2008

Isolation of hydrocarbon degrading denitrifying bacteria from contaminated aquifer material. Abstracts of the Annual Meeting of the American Society for Microbiology 90: 298, 1990

Isolation and characterization of a carbendazim-degrading Rhodococcus sp. djl-6. Current Microbiology 53(1): 72-76, 2006

Isolation and characterization of aniline-degrading Rhodococcus sp. strain AN5. Journal of Environmental Science and Health. Part A Toxic/Hazardous Substances and Environmental Engineering 42(13): 2009-2016, 2007

Isolation and characterization of carbendazim-degrading Rhodococcus erythropolis djl-11. Plos one 8(10): E74810, 2013

Isolation and characterization of 3-N-trimethylamino-1-propanol-degrading Rhodococcus sp. strain A2. Fems Microbiology Letters 296(2): 219-225, 2009

Isolation and characterization of Rhodococcus sp. NB5 capable of degrading a high concentration of nitrobenzene. Journal of Basic Microbiology 51(4): 397-403, 2011

Isolation and characterization of a phenol-degrading Rhodococcus sp. strain AQ5NOL 2 KCTC 11961BP. Journal of Basic Microbiology 53(1): 9-19, 2013

Characterization of methyl tert-butyl ether-degrading bacteria from a gasoline-contaminated aquifer. Bioremediation Journal 6(2): 113-124, 2002

Molecular characterization of phenanthrene-degrading methanogenic communities in leachate-contaminated aquifer sediment. International Journal of Environmental Science and Technology 9(4): 705-712, 2012

Isolation and characterization of a Rhodococcus strain with phenol-degrading ability and its potential use for tannery effluent biotreatment. Environmental Science and Pollution Research International 19(8): 3430-3439, 2012