This study investigated the antiradical and antioxidant potential of the three families of lipopeptides (i.e., surfactin, mycosubtilin, and plipastatin/fengycin) produced by Bacillus subtilis strains. The antiradical/antioxidant activities of highly purified lipopeptides were studied in acellular models using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, superoxide anion ( O 2 . - ), hydrogen peroxide, (H₂O₂) and hydroxyl radical (HO^.). At a lipopeptide concentration of 500 mg.L^-1, the maximum inhibition of DPPH reached 22.88% (obtained for plipastatin). Moreover, the scavenging effects of O 2 . - , H₂O₂, and HO^. at the highest concentration tested (250 mg.L^-1) were found to be 6, 21, and 3% for surfactin, 19, 9, and 15% for mycosubtilin, 21, 18, and 59% for plipastatin, 21, 31, and 61% for the mixture of surfactin/plipastatin, and 13, 16, and 15% for the mixture of surfactin/mycosubtilin, respectively. These results showed that plipastatin was the best candidate due to its antioxidant activities.

Elodie Dussert

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