“…Among the simpler in vitro assays for decay ability are spot tests of a variety of chemicals that give coloured reactions indicating the production by an agar culture of the ligninolytic enzymes laccase, tyrosinase, lignin peroxidase or manganese peroxidase (Fahraeus 1949, Lyr 1958, Nobles 1958, Kaarik 1965, Harkin and Obst 1973, Clemencon 1977, and Niku-Paavola et al 1990). Unfortunately, the composition of the agar medium and the age or growth stage of the culture greatly affect the outcome of such tests (Fahraeus 1952, Hiorth 1965, Schanel 1966, Flodin 1979, Leslie and Leonard 1979, Paranjpe and Chen 1979, Kim et al 1986, Stenlid and Rayner 1989, rendering them rather unreliable. Glenn and Gold (1983) suggested that the clearing of various polymeric dyes structurally related to lignin compounds could be used as an assay of ligninolytic capability in fungi.…”