[Effect of low temperatures (-196 degrees) and of cryoprotectors on some bacterial species]

The effect of low temperatures (-196 degrees C) and cryoprotectors (PEO-400 and glycerol) on the survival, morphological and functional properties was studied with Escherichia coli, Serratia marcescens and Staphylococcus aureus 209. When the cells were frozen for a short period of time in liquid nitrogen, the survival and the rate of protein synthesis decreased in the gram-negative bacteria but remained almost the same in Staphylococcus aureus. PEO-400 and glycerol manifested cryoprotecting action on all the bacteria under study at concentrations which did not harm the bacteria.