Retention of the viability and physiological properties of bifidobacteria during storage by cryopreservation and lyophilization

摘要

Cryopreservation in liquid nitrogen and lyophilization were found to be suitable for a long-term maintenance of B. adolescentis MS-42 cells since both methods provided for the retention of their viability and biological activity. Optimal cooling protocols were designed (freezing of liquid cultures and concentrated cell suspensions with a cryoprotectant at a low cooling rate of 4 degrees C/min or freezing of concentrated cell suspensions without cryoprotectants at a high cooling rate of 100-400 degrees C/min). The introduction of protectants (sucrose, vitamins B, whey, and skim milk) into the freezing medium increased the viability of bifidobacteria and prolonged their shelf life during storage by cryopreservation and lyophilization. [References: 22]