Effect of Soya Lecithin on Solubilization and Biodegradation of Pentachlorophenol by <i>Anthracophyllum discolor</i>

Abstract

The effect of soya lecithin (SL) on solubilization and biodegradation of pentachlorophenol (PCP) by Anthracophyllum discolor was evaluated. Besides, the PCP effect on critical micelle concentration (CMC) of SL and the effect of PCP and SL on the ligninolytic activity of A. discolor w ere evaluated. The PCP solubilization test was performed for 100, 200 and 400 mg · L - 1 with SL solution varying concentrations of ranging from 0 to 0.9 g · L - 1 . The effect of PCP (5 to 20 mg · L - 1 ) on CMC of SL by conductivity was evaluated. The effect of SL (0 to 0.9 g · L - 1 ) on biodegradation of PCP (21.4 mg · L - 1 ) in modified Kirk medium was studied. The results showed that SL addition enhanced PCP solubility in water. The solubilities of 100, 200 and 400 mg · L - 1 of PCP w ere about 4.2, 5.0 and 2.5 times higher than their solubility in pure water when the system was added with 0.9 g · L - 1 of SL. We found that the increase in PCP concentration caused a decrease in the CMC value. In the biodegradation assay, in liquid medium supplemented with 0.9 g · L - 1 of SL, the 94.4% of PCP was biodegraded after 26 days of incubation. In contrast, in the control assay (without SL), the 76.5% of PCP was removed. The PCP degradation was confirmed by the presence of its metabolites. During biodegradation assay, A. discolor mainly produced manganese peroxidase reaching a maximum of 96.8 U · g - 1 (dw) when the culture medium was added with 0.6 g · L - 1 of SL. These results show that SL can be applied to increas ing the bioavailability and biodegradation of PCP.