Fig. 2

Growth characteristics of EGFP-expressing L. plantarum strains. Bacterial cells were pre-cultured to OD₆₀₀ ≈ 0.3. MRS was divided into two equal parts, one in non-induced culture (gray bars) and another in induced culture with 25 ng/mL SppIp (white bars). OD₆₀₀ values were measured 4 h post induction. pLP-pgsA′, pLQa-pgsA′ pLp-S and pLQa-S are the empty vectors without the target proteins, and we only used the pLP-pgsA′ or pLQa-pgsA′ as empty vector control