Cellulolytic potential of thermophilic fungi grown on microcrystalline cellulose. Cellulolytic potential was measured as filter paper degrading activity of secreted fungal enzymes as described in “Methods” for the fungi that had endoglucanase activity. The left y-axis indicates the scale for the upper panel including filter paper degrading activities from all the fungi that and the right y-axis indicates the scale for the lower panel. The filter paper degrading activity from T. leycettanus is truncated. The figure represents the result of triple determination of the enzyme activity for each culture in one growth experiment. Symbols as in Figure 1. See Table 1 for abbreviations of fungal names.