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Biodegradation of nitro-substituted explosives 2,4,6-trinitrotoluene, hexahydro-1,3,5-trinitro-1,3,5-triazine, and octahydro-1,3,5,7-tetranitro-1,3,5-tetrazocine by a phytosymbiotic Methylobacterium sp. associated with poplar tissues (Populus deltoides x nigra DN34).
Van Aken, Benoit; Yoon, Jong Moon; Schnoor, Jerald L.
Afiliação
  • Van Aken B; Department of Civil and Environmental Engineering, The University of Iowa, Iowa City, Iowa 52242, USA. bvanaken@engineering.uiowa.edu
Appl Environ Microbiol ; 70(1): 508-17, 2004 Jan.
Article em En | MEDLINE | ID: mdl-14711682
ABSTRACT
A pink-pigmented symbiotic bacterium was isolated from hybrid poplar tissues (Populus deltoides x nigra DN34). The bacterium was identified by 16S and 16S-23S intergenic spacer ribosomal DNA analysis as a Methylobacterium sp. (strain BJ001). The isolated bacterium was able to use methanol as the sole source of carbon and energy, which is a specific attribute of the genus Methylobacterium. The bacterium in pure culture was shown to degrade the toxic explosives 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazene (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5-tetrazocine (HMX). [U-ring-(14)C]TNT (25 mg liter(-1)) was fully transformed in less than 10 days. Metabolites included the reduction derivatives amino-dinitrotoluenes and diamino-nitrotoluenes. No significant release of (14)CO(2) was recorded from [(14)C]TNT. In addition, the isolated methylotroph was shown to transform [U-(14)C]RDX (20 mg liter(-1)) and [U-(14)C]HMX (2.5 mg liter(-1)) in less than 40 days. After 55 days of incubation, 58.0% of initial [(14)C]RDX and 61.4% of initial [(14)C]HMX were mineralized into (14)CO(2). The radioactivity remaining in solution accounted for 12.8 and 12.7% of initial [(14)C]RDX and [(14)C]HMX, respectively. Metabolites detected from RDX transformation included a mononitroso RDX derivative and a polar compound tentatively identified as methylenedinitramine. Since members of the genus Methylobacterium are distributed in a wide diversity of natural environments and are very often associated with plants, Methylobacterium sp. strain BJ001 may be involved in natural attenuation or in situ biodegradation (including phytoremediation) of explosive-contaminated sites.
Assuntos

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Azocinas / Triazinas / Trinitrotolueno / Methylobacterium / Compostos Heterocíclicos com 1 Anel Tipo de estudo: Risk_factors_studies Idioma: En Revista: Appl Environ Microbiol Ano de publicação: 2004 Tipo de documento: Article País de afiliação: Estados Unidos

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Azocinas / Triazinas / Trinitrotolueno / Methylobacterium / Compostos Heterocíclicos com 1 Anel Tipo de estudo: Risk_factors_studies Idioma: En Revista: Appl Environ Microbiol Ano de publicação: 2004 Tipo de documento: Article País de afiliação: Estados Unidos