Fig. 7

Time-point study and stability of Cry3Aa–PML^VG crystals during the synthesis of biodiesel from WCO. a A time-point study of the transesterification reaction of WCO and MeOH by Cry3Aa–PML^VG crystals. At 2, 4, 8, 24, and 48 h, samples were taken, and the oil layer was analyzed by GC. b Recyclability of Cry3Aa–PML^VG during the production of biodiesel from WCO using 2.0% w/w catalyst. After each cycle, the oil layer was extracted and analyzed by GC, and the crystals were washed with hexane and buffer prior to initiating the next cycle. c Transmission electron microscopy of Cry3Aa–PML^VG crystals before d and after 10 cycles of WCO conversion to biodiesel. Images were taken at ×25,000 and ×30,000 magnification, respectively. All reactions were performed in triplicate and error bars were derived from the standard deviation of the mean