and aeration rate of 300 mL/min; whereas, lipopeptide recovery showed a little reduction to 54%. When increasing aeration rate to 400 mL/min, a high reduction in both enrichment ratio and recovery was found. HPLC profile of lipopeptide extracted from the foamate had less impurity peaks than that from the culture medium(Fig. 7a and b). Thus, the foam fractionation process was able to increase the product purity. The chromatogram of crude lipopeptides showed peaks with retention times similar to the standardsurfactin (98% pure) from Sigma-Aldrich at 11.02, 14.88, and16.36 min (Fig. 7c). Davis et al. [36] also applied foam fractionation technique to separate lipopeptide from culture medium of Bacillussubtilis ATCC 21332. They found that a mean surfactin enrichmentof 2.9 was reached in the cell-free process compared to 1.7 for thecell-containing system and the surfactin recovery for the cell-freeand cell-containing process were similar, 97 and 97%, respectively.