Plate assay for fungal enzymes using cellophane membranes

Fungal mycelia mass and pigments are major obstacles to investigating the secretion of bioactive substances such as enzyme activities using a plate assay. In this study, we applied a cellophane membrane and demonstrated that it can block mycelia mass and conidia (especially pigmented spores that would likely interfere with any subsequent color development-based activity detection) while allowing secreting enzymes to pass through. Visual observation after lifting the cellophane membrane and the collected mycelia and conidia indicated that the bioactivities on specific plates were improved significantly, although some fungal growth hurdle was noted. This proved to be true whether the assays were color development based or not.