A Study on Lipid Removal from Yeast Homogenate by Chemical Pretreatment

Lipids discharged into the yeast homogenate following the cell disruption process have a deleterious impact on the performance of chromatography columns during downstream processing. In this study, the removal of lipids from Pichia pastoris crude extract was investigated using various chemicals at varied concentrations. After treatment of the sample with ۰.۰۵ M borax and ۱.۵% PEI, a lipid reduction of about ۵۲% and ۷۹% was respectively obtained in the flocculated protein. The addition of PEG ۶۰۰۰ to the sample at a final concentration of ۲۰% led to ۵۷% lipid removal. A lipid reduction of ۶۷%–۷۰% was observed when protein precipitation was performed by ۲۰%–۴۰% ammonium sulfate. The efficiency of acetone and diethyl ether for lipid reduction was greater than that of isopropanol, and substantial lipid removal (۹۵%–۱۰۰%) was demonstrated after feedstock treatment with ۰.۵%–۵% acetone and diethyl ether. After conducting detergent lipid dissolution experiments, it was revealed that non-ionic detergents (Triton X-۱۰۰ and Tween ۲۰) at a concentration of ۰.۱% were able to eliminate ۱۰۰% of lipids in the feedstock. Overall, these findings suggest that such chemical treatment strategies may be considered to be used for pre-treating process streams and facilitating related research and applications in downstream processing.

کلیدواژه ها:

Yeast homogenate ، Lipid removal ، Fouling ، Flocculation ، Salt and polymer precipitation ، Solvent and detergent lipid dissolution