FIG 5.

Integration and overexpression of ldh gene enhanced cell growth and LA production. (A) Agarose gel analysis of PCR amplification products of ldh expression cassette in 12 randomly selected colonies. M, DNA ladder; WT, control group with LA412 total DNA as the template. (B) Agarose gel analysis of PCR amplification products of ldh expression cassette in the wild-type (wt) and in pure-genotype P. acidilactici strains obtained after one round of screening. Blue and gray arrows indicate the integrated and the wild-type bands, respectively. (C) DNA sequencing peaks of PCR products of right arm amplified from wt and ldh expression cassette amplified from wt::ldh, respectively. (D) Western blotting of the expression ldh gene. M, Protein ladder. (E) Growth curve of wt and wt::ldh strains, respectively. (F) LA fermentation of wt and wt::ldh strains.