Fig. 3a–e

Effect of culture conditions on titratable acidity and CLA production. a Effect of initial medium pH. Inoculum size was 3 % for La–St and 4 % for La–Lp. b Effect of incubation temperature. Initial medium pH values were pH 6.5 and pH 5.5 for La–Lp and La–St, respectively, in a 36-h fermentation. c Effect of incubation time. Initial medium pH 6.5 for La–Lp at 37 °C and pH 5.5 for La–St at 40 °C. d Effect of inoculum size. Initial medium pH 6.5 for La–Lp at 37 °C and pH 5.5 for La–St at 40 °C, for 48 h fermentation. e Effect of substrate concentration. Reaction system: 5 % (v/v) inoculation size of La–Lp at initial medium pH 6.5, 37 °C for 48 h fermentation, and 3 % (v/v) inoculation of La–St at initial medium pH 5.5, 40 °C for 48 h fermentation