Enhanced Production of a Novel Cyclic Hexapeptide Antibiotic (NW-G01) by Streptomyces alboflavus 313 Using Response Surface Methodology

Abstract: NW-G01, produced by Streptomyces alboflavus 313, is a novel cyclic hexapeptide antibiotic with many potential applications, including antimicrobial activity and antitumor agents. This study developed a system for optimizing medium components in order to enhance NW-G01 production. In this study, Plackett-Burman design (PBD) was used to find the key ingredients of medium components, and then response surface methodology (RSM) was implemented to determine their optimal concentrations. The results of PBD revealed that the crucial ingredients related to the production of NW-G01 were (NH₄)₂SO₄, peptone and CaCO₃. A prediction model has been built in the experiments of central composite design and response surface methodology, and its validation has been further verified. The optimal medium composition was determined (g/L): corn starch 15, glucose 15, peptone 3.80, (NH₄)₂SO₄ 0.06, NaCl 1.5, CaCO₃ 1.30, MgSO₄·7H₂O 0.015, K₂HPO₄·3H₂O 0.015, MnCl₂·4H₂O 0.015, FeSO₄·7H₂O 0.015, and ZnSO₄·7H₂O 0.015. Compared with NW-G01 production (5.707 mg/L) in non-optimized fermentation medium, the production of NW-G01 (15.564 mg/L) in optimized fermentation medium had a 2.73-fold increase.