Abstract
Rhamnolipid and saponin were used as biosurfactant to form cellulase-biosurfactant complex systems. Acetone, ethanol, and methanol were tested recovery solvents, and among the three tested recovery solvents, acetone was the optimum one. Using acetone as recovery solvent and with the addition of 0.1 mM NaCl, the highest protein and activity recovery were yielded. The optimum conditions during the process for cellulase-rhamnolipid complex systems and cellulase-saponin complex systems were discovered. Two cellulase-biosurfactant complex systems were better than the cellulase-AOT complex system. Experimental results showed that biosurfactants have great potential in protein precipitation.