Next, the morphological changes in A. fumigatus in these
media were examined microscopically (Fig. 4). Extension
of mycelia was found to be promoted by laminarin compared
with the control culture. In the medium with sucrose,
glucose, or dextran, a radial form with extensive
branching was noted (Fig. 4i). In the medium with β-
glucan (laminarin, curdlan, or curdlan-oligo), long hyphae
with little branching were observed (Fig. 4j). The average
length between hyphal branch points was measured
at 1 day and found to be greater in the laminarin-added
culture (183.2 ± 58.6 μm; P < 0.01 vs control culture)
than in the control culture (66.6 ± 28.2 μm). These results
reflect morphological changes in A. fumigatus and
suggest that the type of proliferation is changed by adding
β-glucan.