After pre-fixation the mycelia were gently washed with sterilized water and post fixed with osmium tetraoxide dissolved in 50 mM Na–P buffer (pH 6.5). Mycelia were then dehydrated in series of alcohol grades starting from 30% to absolute alcohol, 10 min in every dilution. The dehydrated mycelia were coated with gold using an ion sputter (Coate IB-2, Gike Engineering, Japan) and observed under scanning electron microscope