Effect of Heat Shock-Repair Combined with Trehalose Treatment on Freeze-Drying Survival Rate of Lactiplantibacillus plantarum LIP-1
In this study,the effects of heat shock-repair combined with addition of trehalose in lyoprotectant on the freeze-drying resistance and room temperature storage stability of Lactiplantibacillus plantarum LIP-1 were investigated.The results showed that the freeze-drying survival rate of the combined treatment group with heat shock-repair and 4 g/100 mL trehalose addition was 81.65%,which was significantly higher than those of the control group without heat shock-repair treatment(59.92%)and the heat shock-repair treatment group(70.23%)(P<0.05).The damage degree of cell wall and cell membrane in the combined treatment group was significantly reduced compared with that in the control group.The addition of trehalose maintained a high proportion of unsaturated fatty acids in the cell membrane,reduced cell membrane damage,and significantly enhanced the freeze-drying resistance of the strain while improving its room temperature storage stability.After eight weeks of storage,the survival rate of the combined treatment group was 51.66%,which was significantly higher than those of the control(12.09%)and heat shock-repair(43.79%)groups(P<0.05),and the intracellular fluorescence intensity was 1 969.23±37.22,which was significantly lower than those in the control(3 475.21±106.56)and heat shock-repair(2 843.95±52.12)groups(P<0.05).To sum up,the combined treatment could improve the freeze-drying resistance and room temperature storage stability of the strain.
Lactiplantibacillus plantarum LIP-1heat shock-repairtrehalosefreeze-drying survival ratestorage stability at room temperature