Natural selection for 2,4,5-trichlorophenoxyacetic acid mineralizing bacteria in agent orange contaminated soil.
Biodegradation
; 16(6): 501-12, 2005 Dec.
Article
en En
| MEDLINE
| ID: mdl-15865343
ABSTRACT
Agent Orange contaminated soils were utilized in direct enrichment culture studies to isolate 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and 2,4-dichlorophenoxyacetic acid (2,4-D) mineralizing bacteria. Two bacterial cultures able to grow at the expense of 2,4,5-T and/or 2,4-D were isolated. The 2,4,5-T degrading culture was a mixed culture containing two bacteria, Burkholderia species strain JR7B2 and Burkholderia species strain JR7B3. JR7B3 was able to metabolize 2,4,5-T as the sole source of carbon and energy, and demonstrated the ability to affect metabolism of 2,4-D to a lesser degree. Strain JR7B3 was able to mineralize 2,4,5-T in pure culture and utilized 2,4,5-T in the presence of 0.01% yeast extract. Subsequent characterization of the 2,4-D degrading culture showed that one bacterium, Burkholderia species strain JRB1, was able to utilize 2,4-D as a sole carbon and energy source in pure culture. Polymerase chain reaction (PCR) experiments utilizing known genetic sequences from other 2,4-D and 2,4,5-T degrading bacteria demonstrated that these organisms contain gene sequences similar to tfdA, B, C, E, and R (Strain JRB1) and the tftA, C, and E genes (Strain JR7B3). Expression analysis confirmed that tftA, C, and E and tfdA, B, and C were transcribed during 2,4,5-T and 2,4-D dependent growth, respectively. The results indicate a strong selective pressure for 2,4,5-T utilizing strains under field condition.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Microbiología del Suelo
/
Contaminantes del Suelo
/
Ácido 2,4,5-Triclorofenoxiacético
/
Defoliantes Químicos
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Ácido 2,4-Diclorofenoxiacético
/
Dibenzodioxinas Policloradas
Idioma:
En
Revista:
Biodegradation
Asunto de la revista:
BIOQUIMICA
/
SAUDE AMBIENTAL
Año:
2005
Tipo del documento:
Article
País de afiliación:
Estados Unidos