Table 2. Coded values and combinations tested in the 2k-p fractional factorial designs.

Coded values	pH	Agitation	Surfactants	Cellular growth phase	Temperature (°C)
−1	4.5	Yes	Yes	Exponential	15
1	8.5	No	No	Stationary	45
Combinations
A	4.5	No	Yes	Exponential	45
B	8.5	No	No	Stationary	45
C	8.5	No	No	Exponential	15
D	8.5	Yes	Yes	Stationary	45
E	4.5	Yes	No	Exponential	45
F	4.5	No	Yes	Stationary	15
G	8.5	Yes	Yes	Exponential	15
H	4.5	Yes	No	Stationary	15

Note:

Coded values and combinations tested in the 2k-p fractional factorial designs about the effects of pH, temperature, cellular growth phase, agitation and presence of surfactants on biofilm formation by B. infantis DSM20088 and L. reuteri DSM20016.