Fig. 6

Structural characteristic and function determination of surfactin with different compositions. A HPLC analysis of purified C14-rich surfactin, C15-rich surfactin and commercial standard surfactin. Peaks 1, 2, and 3 represent the liquid chromatographic peaks of C13, C14, and C15 surfactin homologues, respectively. The HPLC analysis of C14–C15-rich surfactin produced in this study reveals significantly elevated peak 2–3 intensities compared to commercially available surfactin standards, respectively. B Hemolytic and antibacterial activity analysis of purified C14-rich surfactin, C15-rich surfactin and commercial standard surfactin. C15-rich surfactin exhibited exceptional hemolytic and antibacterial activity compared to standard surfactin. C, D Emulsifying activity of surfactin with different compositions against different substrates of GTCC, glycerol triacetate, hexadecane, and liquid paraffin. C14-rich surfactin exhibited exceptional emulsifying activity compared to standard surfactin and C15-rich surfactin, especially against hexadecane