The growth pattern of probiotics can be modified by changing their nutritional factors and their physiological stage. Meanwhile, high intensity ultrasound (HIUS) can be employed to increase probiotics’ biomass. The one-factor-at-a-time (OFAT) approach was employed to investigate the influence of the growth medium (MRS broth, whole milk, and skim milk), culture age (1 day and 7 days old) and ultrasound parameters (time and amplitude) on the kinetic parameters of L. acidophilus. The oldest culture (7 days) had a greater lag phase and time to reach the end of the sigmoidal curve (Tmax) (p max) compared to the youngest culture (1 day). Regarding the growth medium, skim milk presented the greatest L. acidophilus counts (p max and Tmax. When 30% amplitude was applied, a greater μmax and a smaller Tmax were observed (p L. acidophilus. Results from this study could be used in the design and optimization of processes to improve the growth of the probiotic L. acidophilus at industrial scale.
