TNT biotransformation and detoxification by a Pseudomonas aeruginosa strain

Authors

Byung-taek Oh, Seoul National University, Seoul, Korea
Patrick J. Shea, University of Nebraska-LincolnFollow
Rhae A. Drijber, University of Nebraska-LincolnFollow
Galina K. Vasilyeva, Russian Academy of Sciences, Pushchino, Russia
Gautam Sarath, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

9-8-2003

Comments

Published in Biodegradation 14: 309–319, 2003.

Abstract

Successful microbial-mediated remediation requires transformation pathways that maximize metabolism and minimize the accumulation of toxic products. Pseudomonas aeruginosa strain MX, isolated from munitionscontaminated soil, degraded 100 mg TNT L^-1 in culture medium within 10 h under aerobic conditions. The major TNT products were 2-amino-4,6-dinitrotoluene (2ADNT, primarily in the supernatant) and 2,2′- azoxytoluene (2,2′AZT, primarily in the cell fraction), which accumulated as major products via the intermediate 2-hydroxylamino-4,6-dinitrotoluene(2HADNT). The 2HADNT and 2,2′AZT were relatively less toxic to the strain than TNT and 2ADNT. Aminodinitrotoluene (ADNT) production increased when yeast extract was added to the medium. While TNT transformation rate was not affected by pH, more HADNTs accumulated at pH 5.0 than at pH 8.0 and AZTs did not accumulate at the lower pH. The appearance of 2,6-diamino-4-nitrotoluene (2,6DANT) and 2,4-diamino-6-nitrotoluene (2,4DANT); dinitrotoluene (DNT) and nitrotoluene (NT); and 3,5-dinitroaniline (3,5DNA) indicated various routes of TNT metabolism and detoxification by P. aeruginosa strain MX.