and then allow to
thaw naturally at room temperature.
Test stock cultures
were preserved for more than 10 years by this preservation
method without any programmed precooling and rapid
thawing for their cryopreservation.
Most of the test fungi
could survive for 5 years in medium containing 10% glycerol
even after alternate freezing and thawing at intervals of
6 months.
When a strain of Flammulina velutipes was tested
for mycelial growth rate and productivity of fruit-bodies
after cryopreservation for 3 years, the fungus reproduced
with its initial capability.
These results demonstrate that the
sawdust-freezing method using a cryoprotectant is expected
to be a reliable and easy preservation method for fungus
stock cultures.