Figure captions
Fig. 1. Sophorolipids produced by C. bombicola . A. Acidic-form SLs; B. Lactone-form SLs. These structures can be non-(R1, R2=-OH), mono-(R1=-OH, R2=-OCH3), or di-acetylated (R1, R2=-OCH3). (Chen et al., 2020)
Fig. 2.Semi-continuous fermentation platform (a. Fermentation broth inlet; b. Supernatant outlet; c. SLs export).
Fig. 3.The morphology and sedimentation of SLs at different O/S ratios.
Fig. 4. SLs precipitation. A. Relationship between the sedimentation height ratio of SLs and the concentration. B. Relationship between the average sedimentation rate of SLs and O/S.
Fig. 5.Parameters related to SLs precipitation. A. SLs particle size. B. Viscosity of fermentation supernatant. C. Density of SLs and oil mixture. D. Density of fermentation broth supernatant.
Fig. 6. Mechanism of SLs sedimentation.
Fig. 7. Ultrasonic assisted SLs deposition. A. 100 W ultrasonic power. B. 200 W ultrasonic power. C. 300 W ultrasonic power. D. Maximum sedimentation rate at different power.
Fig. 8.Ultrasound-assisted in-situseparation. A. SLs titer. B. Residual oil, glucose and DCW concentration. C. Productivity and yield of SLs.