Preparation and regeneration of protoplasts of three fungi of Boletaceae

Protoplasts of three fungi of Boletaceae, Suillus luteus, S. grevillei, and Boletinus cavipes, were prepared with yields of 45, 8.0, and 1.8×107/g fresh mycelia under the optimal conditions, respectively. Nucleate protoplasts accounted for 42% of the whole preparation of S. luteus and 32% of that of S. grevillei, and 21% of the nucleate protoplasts of S. luteus and 35% of those of S. grevillei possesed two nuclei. Regeneration efficiency of protoplasts was 0.4% for S. luteus and 0.05% for S. grevillei, The regeneration of B. cavipes protoplasts was also confirmed. Optimal conditions for regeneration were determined. Addition of gellan gum instead of agar to the medium and activated charcoal treatment of agar medium increased the regeneration efficiency significantly.