Fig. 8

Growth and pH assessments of L. crescens cultures in Hi-GI medium using four biological buffers. These buffers include Monosodium phosphate (NaP), ACES, Bis-Tris HCl (Bis), and MES at 10, 25 and 50 mM concentrations. L. crescens was grown to exponential phase in Hi-GI at 250 rpm, 28 °C (OD₆₀₀~0.7–0.8, Fig. 16) and washed with a sterile ACES-KOH buffer pH 6.5 prior to inoculation in Hi-GI with the different buffers at an initial pH of 5.92. Phosphate, MES and Aces at 10 mM promoted the growth of L. crescens at similar rates to those of the Hi-GI control. Increase of the external pH was evident in all the media, even at 50 mM concentrations of the buffers. a Cell growth represented as optical density, b Cell growth in Logarithmic (log2) scale of the optical density, and c pH of the external medium over time during cell growth