Fig. 3

Relative gene expression levels. a The relative expression levels of efflux pump encoding genes in DC8358, the expression of ydcV (fold-changes: ydcV, 5.71 ± 0.68) was increased; b The relative expression levels of efflux pump encoding genes in DC8419, the expression of ydcV, yihV, and acrB (fold-changes: ydcV, 8.74 ± 0.61; yihV, 3.57 ± 0.52; acrB, 3.44 ± 0.21, respectively) was increased; c The relative expression levels of efflux pump encoding genes in DC8424, the expression of ydcU, ydcS, yihV, acrD, and mdfA (fold-changes: ydcU, 4.71 ± 0.13; ydcS, 2.8 ± 0.42; yihV, 6.82 ± 0.65; acrD, 2.63 ± 0.14; mdfA, 5.13 ± 0.26, respectively) was increased; d The relative expression levels of efflux pump encoding genes in DC8724, the expression of ydcT, ydcU, ydcS, cysP, and yihV (fold-changes: ydcT, 6.56 ± 0.56; ydcU, 18.25 ± 1.36; ydcS, 8.76 ± 0.49; cysP, 3.89 ± 0.2; yihV, 2.00 ± 0.03, respectively) was increased. The values of three biological repeats represent the mean ± SD. *indicates the gene overexpression, which is the relative expression level increased by 2-fold or greater in comparison to that of the control strain ATCC 25922