Improvement of Fengycin Production by Bacillus amyloliquefaciens via Promoter Replacement at the Fengycin Operon with the P-59 and P-repU Promoters

In this present study, a method was established to enhance the production of fengycin by Bacillus amyloliquefaciens ES-2 via replacement of the native promoter of the pps operon with one of two constitutive promoters, P-59 and P-repU. This resulted in the production of two recombinant bacteria, B. amyloliquefaciens ES-2-1 and ES-2-2, that contained the P-59 and P-repU promoters, respectively. Bioassays against Aspergillus oryzae and Rhizopus stolonifer confirmed increases in fengycin production in the recombinant strains. Furthermore, enhanced fengycin production was validated by high performance liquid chromatography (HPLC), and HPLC peaks for recombinant B. amyloliquefaciens ES-2-1 and ES-2-2 showed similar patterns of lipopeptides to the wild type strain. Fengycin production in B. amyloliquefaciens ES-2-1 and ES-2-2 was increased compared to the wild type strain by 65% and 20%, respectively. These results demonstrate the possibility to increase fengycin production by replacement of the native promoter of the pps operon.