Fig. 3.

(A) Using UV and NTG treatments to induce random mutations, followed by selection with antimycin and 6’-azauracil, we identified the BMZF4 strain, which exhibited significantly increased 2’-FL production. This approach effectively enhanced the genetic diversity, allowing us to isolate a highly productive mutant strain. (B) Genes encoding lactose permeases derived from K. lactis, P. megaterium, and E. coli were overexpressed in vector form, leading to the creation of strains BMZF5 through BMZF7. The 2’-FL production levels of each of these strains were subsequently measured to evaluate the effectiveness of lactose permease overexpression in improving 2’-FL synthesis