Abstract
This study focused on the mycotransformation of a very prominent PAH, anthracene, and its acute toxicity reduction by Ascomycete fungi: Trichoderma lixii strain FLU1 ( Tl FLU1) and Talaromyces pinophilus strain FLU12 ( Tp FLU12), indigenously isolated from benzo[b] fluoranthene-enriched activated sludge. The results indicate that both the isolates Tl FLU1 and Tp FLU12 could tolerate anthracene exposure up to 1000 mg/L, with increased expression of ligninolytic enzymes: Laccase, Lignin peroxidase, and Manganese peroxidase. The mycotransformation of anthracene was observed to be growth-linked and mediated by the expression of the intracellular enzymes as the initial mechanism used by these strains followed by the ligninolytic enzymes with up to 56% and 38% anthracene degradation by Tl FLU1 and Tp FLU12, respectively, after 24 days with a concomitant change in pH from 5 to 4 ( Tl FLU1) and 6.2 ( Tp FLU12). The GC–MS and FTIR analysis of the samples indicate the appearance of metabolic intermediates: 9,10 anthracenedione and benzoic acid in Tl FLU1 grown medium, while anthrone and 9,10 anthracenedione were detected in Tp FLU12 grown medium. The mycotransformation of the compound followed a first-order kinetic model with an effective concentration (EC 50 ) of 262.3–266.1 mg/L, with a toxicity unit (TU) of 0.4% in Vibrio parahaemolyticus (6 h exposure) to each intermediate. Results show efficient mycotransformation of anthracene into a non-toxic state by Tl FLU1 and Tp FLU12.