Potency of Phlebia species of white rot fungi for the aerobic degradation, transformation and mineralization of lindane

The widespread use of the organochlorine insecticide lindane in the world has caused serious environmental problems. The main purpose of this paper is to investigate the potency of several Phlebia species of white rot fungi to degrade, transform and mineralize lindane, and to provide the feasibility of using white rot fungi for bioremediation at contaminated sites. Based on tolerance experiment results, Phlebia brevispora and Phlebia lindtneri had the highest tolerance to lindane and were screened by degradation tests. After 25 days of incubation, P. brevispora and P. lindtneri degraded 87.2 and 73.3% of lindane in low nitrogen medium and 75.8 and 64.9% of lindane in high nitrogen medium, respectively. Several unreported hydroxylation metabolites, including monohydroxylated, dehydroxylated, and trihydroxylated products, were detected and identified by GC/MS as metabolites of lindane. More than 10% of [C-14] lindane was mineralized to (CO2)-C-14 by two fungi after 60 days of incubation, and the mineralization was slightly promoted by the addition of glucose. Additionally, the degradation of lindane and the formation of metabolites were efficiently inhibited by piperonyl butoxide, demonstrating that cytochrome P450 enzymes are involved in the fungal transformation of lindane. The present study showed that P. brevispora and P. lindtneri were efficient degraders of lindane; hence, they can be applied in the bioremediation process of lindane-contaminated sites.