CHLOROPHENOL DEGRADATION BY PHANEROCHAETE-CHRYSOSPORIUM

Degradation of chlorophenols by P. chrysosporium in static cultures ha s been studied. The influences of mycelium acclimation, co-substrate c oncentration and nitrogen source on phenol degradation were analyzed. With non-acclimated mycelium the maximal concentrations degraded were 150 ppm of o-chorophenol and 100 ppm of the isomers m- and p-chlorophe nol. The substituted ortho-position on the aromatic ring was the prefe rred attack position. Meta- and para-positions were less reactive and resulted in a slower degradation rate than the ortho position. Neverth eless, with acclimated mycelium, an increase in the ability to degrade chlorophenol and a higher reactivity in meta- and pam-positions were observed (degraded chlorophenol increased by up to 70% for the o-isome r and 50% for the m- and p-isomers with respect to non-acclimated myce lium). A decrease in glucose concentration caused a decrease in chloro phenol degradation rare. Twelve days were needed for complete degradat ion of o-chlorophenol with 10 g/l of glucose and 22 days when glucose concentration was decreased to 2.5 g/l. The reduction of ammonium tart rate caused a greater lag time, but not a decrease in chlorophenol deg radation rate. Replacement of ammonium tartrate by ammonium chloride c aused a decrease in chlorophenol degradation rate. (C) 1997 Elsevier S cience Ltd.