3.1 Hemolytic activity of surfactin
Surfactin has strong hemolytic activity [20]. We detected the
hemolytic activity of surfactin using the agar plates containing sheep
blood cells, and found WH1 showed obvious hemolytic activity around the
colony, but the mutant strain ΔsrfA without surfactin production
lost this ability. We further determined the hemolytic activity in
broth, and found it was also disappeared in ΔsrfA (Fig. S1 in
supplementary materials). Thereby, the hemolytic activity could be used
for representation of the surfactin production in different strains.