Factor

Lower Growth Limit

Optimum^b

Upper Growth Limit

Can Survive^c (No Growth)

Temperature (˚C)

−1.5 to +3.0

30.0 to 37.0

45.0

−18.0

pH^d

4.2 to 4.3

7.0

9.4 to 9.5

3.3 to 4.2

Water Activity (a_w)

0.90 to 0.93

0.99

>0.99

<0.90

Salt Concentration ^e(%)

<0.5

0.7

12 - 16

≥20

Atmosphere

Facultative anaerobe (it can grow in the presence or absence of oxygen, e.g. in a vacuum or modified atmosphere package)

Heat Treatment during Food Processing

A temperature/time combination e.g. of 70˚C and 2 min is required for a D6 (i.e. 106 or 6 decimal) reduction in numbers of L. monocytogenes cells. Other temperature/time combinations may also provide the same reduction