Influence of freezing temperatures prior to freeze-drying on viability of yeasts and lactic acid bacteria isolated from wine

• DOI: 10.1111/jam.13465
• Publication Date: 2017-04-05T16:59:33Z
• Authors: L. Polo; R. Mañes-Lázaro; I. Olmeda; L.E. Cruz-Pio; Á. Medina; S. Ferrer; I. Pardo
• Keywords: 0303 health sciences; 660; yeasts; Wine; freezing; survival; lactic acid bacteria; Cold Temperature; 03 medical and health sciences; Freeze Drying; Species Specificity; Stress, Physiological; Yeasts; freeze-drying; Lactic Acid; wine

To determine the effect of three different freezing temperatures on post‐freeze‐drying survival rates wine yeasts and lactic acid bacteria (LAB). know if a similar freeze‐drying protocol can be used for both micro‐organisms. Cells from liquid culture media were recovered concentrated in appropriate lyoprotectants. Aliquots each strain frozen at −20, −80 −196°C before vacuum drying. Viable cell counts done after freeze‐drying. Survival calculated. Freezing differently affected yeast survival. The highest obtained −20 −80°C yeasts, but LAB. Major differences recorded among freeze‐dried less drastic Yeasts Pichia membranifaciens, Starmerella bacillaris Metschnikowia pulcherrima, LAB Lactobacillus paracasei, Pediococcus parvulus mali, most tolerant species to freeze‐drying, regardless temperature. Yeast differed tested For −20°C ensured viability temperature freeze‐dry cells is crucial factor ensuring good These results are important appropriately preserving micro‐organisms improving starter production processes.