Polyamine and Laccase Production under Cadmium Stress in Trametes (Coriolus) versicolor and Funalia trogii

In the present study the effect of increasing the concentrations of the heavy metal cadmium (Cd) (0.1-200 ppm) on the free polyamines (PAs) level and laccase activity was studied in the white rot fungi Trametes (Coriolus) versicolor and Funalia trogii at 6 and 15 days. Spermidine (Spd) was the most abundant PA in the two white rot fungi, while Spermine (Spm), and Putrescine (Put) were found only in trace amounts or were not determined. The highest Spd levels (1952.05 μg/DW and 2391.54 μg/DW) were observed in 1 ppm Cd at 15 days of incubation in T. versicolor and F. trogii respectively. The laccase activity of both species, especially in the 15-day cultures, showed a significant increase compared to the control. The highest increase was evident at 100 ppm Cd where the laccase activity was over 19 fold higher than that of the control sample in the 15 day culture of T. versicolor. The dry biomass in the 0.1 and 1 ppm Cd concentrations showed a significant increase in T. versicolor in the six and 15 day incubation periods. In all cases, the dry biomass in both the six and 15 day cultures of F. trogii showed a significant increase compared to the control cultures. The findings gathered through this study show that Cd can amplify free Spd levels and increase laccase activity in T. versicolor and F. trogii. This increase under Cd stress suggests their possible role in combating