Viability of Mold Cultures Stored at — 20° C

Abstract

Fungus cultures on agar slants may be preserved by simply placing them in a freezer at – 17° C to – 21° C. Cultures from a general collection of Hyphomycetes, Zygomycetes, Ascomycetes and yeasts were checked for viability after varying periods of freezer storage. Of 100 strains stored for one year, only one did not grow when thawed and transferred to fresh culture medium. Of 400 strains stored for two years, seven were not viable and one was contaminated. Of 100 strains stored for three years and nine months, three were not viable. Of 291 strains stored for five years, fifteen were not viable. This method was found to be suitable for certain fungi which do not survive the freezedrying process.