CRYOPRESERVATION OF YEASTS AND MOLDS CULTURES FROM CHEESE FACTORIES

A bibliographic study upon different storage techniques for yeasts and molds has showed that the deep-freezing process brought best garanties. A preliminary study on some representative strains from cheese fongic flora made it possible to establish the storing diagram. Fifty seven easts strains belonging to genus and species commonly encountered among cheese, 15 Geotrichum candidum strains, 15 Penicillium caseicolum and 15 Penicillium roqueforti, were tested. After an approximate one year storage period, the cell survival rate measure and the metabolic potential for different strains on API ZYM and API 50CH systems were estimated. A -80-degrees-C (or -196-degrees-C) cryopreservation, followed by a -196-degrees-C storage, whatever cryoprotector used, ensured, in most cases a good storage result for cell viability and preliminary physiological and biochemical characteristics stability.