The use of heavy metals in mycoremediation of synthetic dyes

Abstract

Abstract Synthetic dyes represent a major class of toxic pollutants that are resistant to biological degradation, and heavy metals play a special role in this process. In this study, two isolates of lignicolous macromycetes, Lenzites betulina as well as another species less frequently studied, Trametes gibbosa, were tested in order to assess their remediation potential against three different synthetic dyes under specific conditions. The effect of heavy metal ions in the discoloration of synthetic dyes process, and the optimal concentration of manganese ions necessary were evaluated. The dyes’ discoloration efficiency of the fresh isolates were compared to the isolates maintained by refrigeration, isolates that were repeatedly sub-cultivated and isolates that were previously grown on dye-supplemented media, and then were assessed. The discoloration process was evaluated in liquid nutrient media, 10 replicates were used for each working version. Evaluation of discoloration rate was obtained by using a UV-VIS spectrometer. The results were interpreted statistically by the Kruskal-Wallis test and by use of a new complex method, Multiple Factor Analysis. The fresh isolates showed the highest discoloration capacity while the isolates previously grown on the dye-supplemented media presented a low discoloration rate. Manganese ions gave a positive effect on enzyme induction while copper and cobalt ions inhibited the process.