2025 Volume 51 Issue 6 Pages 221-229
Copper has antimicrobial properties and is used as one of the main components in wood preservatives. However, some wood decay fungi are known to exhibit resistance to copper. To investigate fungal responses to copper, we first cultured fungi on a copper-free cellophane agar medium in Petri dishes. We then transferred the fungi, along with the cellophane film, to a copper-containing agar medium and observed their subsequent behavior. The fungi used in this study were Fomitopsis palustris and Trametes versicolor, both of which are designated as test fungi in the JIS K 1571 test standard. As a result, irreversible damage to the hyphae of both fungi was observed two days after transfer onto the copper-containing agar medium. However, four days after the transfer, copper accumulation was detected around the hyphae of F. palustris, forming an insoluble deposit, and new hyphal growth was also observed. On the other hand, no copper accumulation was observed around the hyphae of T. versicolor, and hyphal growth remained halted even seven days after the transfer. From the above, the method using cellophane agar medium enabled the visual clarification of the differing copper responses of the two fungi.
