Basidiomycete cryopreservation on perlite: Evaluation of a new method

A new cryopreservation method using perlite as a carrier was evaluated on a large set of mycelial cultures of basidiomycetes. The viability and some other characteristics—growth, macro- and micromorphology, and laccase production—of 442 strains were tested after 48-h and then after 3-year storage in liquid nitrogen using a perlite protocol (PP). All (100%) of them survived successfully both 48-h storage and 3-year storage in liquid nitrogen without noticeable growth and morphological changes. Also laccase production was unchanged. The viability and laccase production of a part (250) of these strains were compared with those of the strains subjected to an original agar plug protocol (OP). Using OP, 144 strains (57.6%) out of 250 survived a 3-year storage in liquid nitrogen. The results indicate that the cryopreservation protocol used significantly influences survival of the strains. Markedly better results were achieved using the PP.