Microbial responses to xenobiotic compounds. Identification of genes that allow Pseudomonas putida KT2440 to cope with 2,4,6-trinitrotoluene.
Bottom Line: Response to TNT stress is regulated at the transcriptional level, as significant changes in the level of expression of 65 genes were observed.Of these genes, 39 appeared upregulated, and 26 were downregulated.The ORF PP1232 whose transcriptional level did not change in response to TNT affected growth in the presence of nitroaromatic compounds and it was found in a screening of 4000 randomly generated mutants.
Affiliation: Bio-Iliberis Research and Development, Edificio BIC, Parque Tecnológico de Ciencias de la Salud, E-18100 Armilla, Granada, Spain.Show MeSH
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Mentions: The growth of P. putida KT2440 in liquid M9 minimal medium with glucose as a carbon source under aerobic conditions was tested in the presence of increasing concentrations of TNT (0.14, 0.29, 0.43 and 0.58 mM). Results revealed that KT2440 grew with a doubling time of about 60 min even in M9 TNT‐saturated medium (0.58 mM). The growth yield in the absence of TNT and in the presence of up to 0.43 mM TNT was 1.1 ± 0.1 mg dry weight ml−1; however, the growth yields of cultures (Fig. 1) grown in the presence of 0.58 mM were consistently 10–15% lower than in the absence of the nitroaromatic or in the presence of lower concentrations. The resilient ability of P. putida to thrive in the presence of high TNT concentrations is illustrated by comparison with Stenotrophomonas sp. OK‐5, an isolate from TNT‐contaminated soils, which cannot sustain TNT concentrations above 0.4 mM (Ho et al., 2004), and the unicellular green algae Chlamydomonas reinhardtii, which does not survive at TNT concentrations as low as 0.01 mM (Patel et al., 2004).
Affiliation: Bio-Iliberis Research and Development, Edificio BIC, Parque Tecnológico de Ciencias de la Salud, E-18100 Armilla, Granada, Spain.