Culture Maintenance

Before 1970, cultivars used for commercial spawn production were maintained on various agars or cereal grains with periodic subculturing of growing mycelium to a fresh medium. This method, for the most part, was reliable, although spawn makers and researchers reported cases of culture degeneration periodically. In 1970, researchers successfully preserved and maintained stability of spawn stocks of A. bisporus stored in liquid nitrogen. Several research reports on culture maintenance verified the suitability of cryogenic preservation, fundamentally changing the way spawn makers handled their cultures used for commercial spawn production. In practice, cryogenic preservation is used to ensure use of superior spawn-starter cultures. Many vials (perhaps as many as 200 to 300) containing spawn or mycelium from cultures of promising spawn lines are stored in liquid nitrogen. Following successful testing of the spawn lines at both pilot plant and commercial testing facilities, the spawn maker can easily reproduce the superior lines many times during subsequent years.

3059 view.