Fig 4.
RT-qPCR analysis of the arc genes (arcA, arcB, arcC, arcT, arcD, and arcR [from left to right, respectively, for each set of bars]) (A) and a putative second arc operon (LSA0067, LSA0068, LSA0069, LSA0070, LSA0071, and LSA0072 [from left to right, respectively, for each set of bars]) (B) in Lactobacillus sakei 23K in modified MRS medium supplemented with 3 g liter−1 (17.2 mM) of arginine during different growth phases (late exponential [OD600, 0.3], end exponential [OD600, 0.5], early stationary [OD600, 0.9], and late stationary [OD600, 1.0 after 24 h of fermentation] growth phases) at pH 6.0. Data shown are mean values ± standard deviations from four independent fermentation experiments. No significant differences were found for the relative expression levels of the genes of the second putative arc operon compared to the control fermentations, except for LSA0072, which showed a significant (P < 0.001) decrease of expression in the stationary growth phase.