Using frozen lactic acid bacteria in the atmosphere of liquid nitrogen can increase the number of living cells and has no effect on the ratio of bacterial cultures in the starter.
Scientific-technical principles and an experimental model system for kriozamorazhivaniya microbial biomass.

An experimental setup for kriozamorazhivaniya biomass, a schematic diagram is shown in Figure 1. Biomass is placed in the chamber 2 a working volume of 2.5 liters, which is connected to a cylinder containing helium gas. At a helium pressure on biomass P ~ 0.1 atm. mass is forced through a nozzle containing 37 capillaries of diameter d = 2mm and a length L = 25mm (Fig. 2), then falling to low-temperature gas atmosphere of liquid nitrogen.

Fig. 1 Equipment for kriozamorazhivaniya microbial biomass: 1 - container with an inert gas (helium), 2 - camera 3 - biomass, 4 - stainless steel wire mesh, 5 - formed particles of biomass, 6 - aluminum Dewar flask capacity 50 liters, 7 - liquid nitrogen

Fig. 2 Nozzle with capillary

Dewar 6 contains the liquid nitrogen 7 and the drive to form a mesh cylinder 4. When jacking of biomass derived particles with a diameter D = 2,5-3,0 mm, with the capacity of the unit 20 -25 kg per shift, depending on the consistency of the masses. Further, the particles obtained packaged in a container zaholozhennye for further processing.