Protective formulation

Viable cell concentration before freeze-drying (CFU/mL)

Viable cell concentration after freeze-drying (CFU/mL)

Survival rate (%)

Control

3.4 × 10¹¹ ± 0.3

3.6 × 10¹⁰ ± 0.3

10.5 ± 1.2

Betaine

3.5 × 10¹¹ ± 0.4

1.3 × 10¹¹ ± 0.2

37.1 ± 5.0

Glutamate

3.2 × 10¹¹ ± 0.2

1.1 × 10¹¹ ± 0.3

33.1 ± 9.4

Sucrose

3.5 × 10¹¹ ± 1.4

1.4 × 10¹¹ ± 0.5

39.5 ± 14.3

Sorbitol

3.4 × 10¹¹ ± 0.6

2.7 × 10¹¹ ± 0.5

80.5 ± 15.8

Trehalose

4.0 × 10¹¹ ± 0.2

1.8 × 10¹¹ ± 0.3

44.4 ± 7.5