Influence of the extent of disruption of Bakers' yeast on protein adsorption in expanded beds.

摘要

Factors affecting the use of expanded bed adsorption (EBA) chromatography for downstream processing of microbial fermentations were studied using bakers' yeast cultures with total proteins and alpha-glucosidase as model protein products. Cells were disrupted by high pressure homogenization or hydrodynamic cavitation, and 2 adsorbents were tested (anionic Streamline DEAE and cationic Streamline SP). Following disruption, the feedstock was analysed for pH, viscosity, conductivity, particle size distribution and levels of protein and alpha-glucosidase. Sorption performance of the anionic adsorbent was affected by electrostatic interactions with cell debris and by intraparticle diffusional resistances in the adsorbent matrix. The intensity of cell disruption also affected sorption of target proteins and levels of non-specific binding. It is concluded that optimization of the selective recovery of intracellular products by EBA requires more research into the effects of disruption intensity and the influence of cell debris and sorbent-protein interactions.