Conversion of 4-Chlorophenoxyacetic Acid by the Pseudomonas sp. 36DCP Strain

Resumo

The new natural 36DCP strain, which is capable of using 4-chlorophenoxyacetic acid (4-CPA) as the sole source of carbon and energy, was characterized. A culture isolated from a soil sample contaminated with chemical waste was identified according to physiological, biochemical, cultural, morphological features and analysis of the 16S rRNA gene sequence as a strain belonging to the Pseudomonas genus. In the batch culture, Pseudomonas sp. 36DCP degraded 45% of 4-CPA from the initial concentration after 5 days of incubation. Based on the identified intermediate metabolites in the culture medium (para-benzoquinone and hydroquinone), it was found that the conversion of 4-CPA in Pseudomonas sp. 36DCP proceeds through the hydroquinone pathway. This degradation pathway of monochlorinated phenoxyacetic acids has not previously been described in bacteria.