Response of Pseudomonas species from Contaminated Soils to Selected Organic (Synthetic) Pesticides

Abstract

Growth response profile of three species of Pseudomonas isolated from pesticide contaminated soils within Uyo, Nigeria was studied using standard microbiological and analytical techniques. The ability of the isolates to tolerate varying concentrations of commercially available pesticides namely; Decis, DD force and Cyperforce was assessed over a 96 hour period. Selective enrichment cultures with graded concentrations of the pesticides were used to assay their growth response profile and the absorbance determined using CO75 digital colorimeter. The results showed that the Pseudomonas species differed biochemically. Their growth response at pesticide concentrations 0.0001, 0.001, 0.01, 0.1, 1 and 10% v/v differed significantly (P<0.05) at 24 hours interval for four days. At 10% concentration of Decis pesticide over 96 hour, the absorbance were 0.20, 0.23 and 0.30 for Pseudomonas from Agriculture research farm, hospital dumpsite and municipal waste dump site respectively. This ability therefore offers a veritable tool for use in the bioremediation and ultimate restoration of pesticide contaminated soils but however requires further evaluation.