Fig. 3

Effect of pH on (a) 1B-23 culture growth, (b) crude extract mass per 10 mL culture and (c) total surfactin accumulation over time. B. velezensis 1B-23 was grown at pH 5.0 (black, solid line), pH 6.0 (black, dashed line), pH 6.5 (black, dotted line), pH 7.0 (grey, solid line), or pH 8.0 (grey, dotted line), at 16 °C. The results for each treatment are represented as the mean value of each replicate minus the abiotic negative control ± SD, n = 4