Effect of pH and inoculum size on PCP degradation by Pseudomonas aeruginosa

WOLSKI E. A; MURIALDO S. E.; GONZALEZ F. J

Carlos Paz, Córdoba, Argentina

Congreso; XXXVIII REUNION ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIONES EN BIOQUIMICA Y BIOLOGIA MOLECULAR (SAIB).; 2002

SOCIEDAD ARGENTINA DE INVESTIGACIONES EN BIOQUIMICA Y BIOLOGIA MOLECULAR (SAIB).

Pentachlorophenol (PCP) has been used as a wood preservative, insecticide and herbicide. This persistent polychlorinated aromatic compound is toxic to numerous organisms and persists in water and soil for a longer time. Therefore, there is a need to decontaminate the PCP laden soils. Using microorganism for bioremediation of PCP-contaminated sites is of interest. The success of bioremediation may depend on the physiological and biochemical properties of PCP-degrading bacteria. The understanding of these properties is required before optimum use of bacteria in environmental application. The aim of this study was to evaluate the influence of pH of the medium and the effect of inoculum size on pentachlorophenol degradation by Pseudomonas aeruginosa. PCP degradation was assessed by measuring the decrease of absorbance at 320 nm (a peak corresponding to PCP) and a kinetic study of PCP degradation were performed. At pH values of 6,3; 7,1 and 8 PCP was degraded rapidly. While at pH 5,5 the decrease of PCP was more slowly. At pH 6,3 the specific consume of PCP (mg/h/CFU) by P. aeruginosa was greater than for the other values of pH. PCP was degraded in all cases and PCP degradation increased with increasing of inoculum size. But the cultures inoculated with the lowest inoculum size showed the highest specific consume.