Continuous aqueous phase extraction of proteins: Automated processing and recycling of process chemicals

Abstract

A two-stage aqueous phase extraction of the enzyme fumarase from baker's yeast is described with respect to the recycling of the upper effluent phase from the secondary extraction. It was found that the binodal curve position was only slightly altered by the presence of protein at different load levels and that enzyme specific activity in the product was improved at higher total protein concentrations, which simplified the recycling strategy. On-line enzyme and protein assays showed that disturbances during start-up and desludging operations were reflected in variations in the protein concentrations in the various streams, but that the enzyme activities remained relatively stable. Recycling reduced the polyethylene requirements by 50% and that for potassium phosphate by 12%. A maximum saving of PEG (polyethylene glycol) of approximately 70 YO was achieved at optimum conditions of extraction, compared to a value of 90% predicted by a theoretical description of the system. An economic analysis of the recycled process showed significant advantages compared with a non-recycled system, even though the capital outlay requirements for an automated, continuous system are much higher than for a manually run process.

Aqueous two-phase systems extraction of α-toxin from Clostridium perfringens type A

“…Several advantages are reported, including low cost, good reproducibility, easy scale-up and recycling of the phases [11].…”

Dispersed phase hold-up in a Graesser raining bucket contactor using aqueous two-phase systems

“…It offers distinct advantages over classical methods of protein purification, such as protein fractional precipitation and centrifugation (Papamichael, Boerner, & Husted, 1992). Some ATPS advantages include, low material costs, good reproducibility, minimal protein denaturation and easy scale-up (Kula, Kroner, & Husted, 1982).…”

Kinetic model for simultaneous cell disruption and aqueous two‐phase extraction

“…The salt may be ammonium sulfate or potassium phosphate. The biphasic system has been used to extract and purify intracellular enzymes on a large scale,9, 10 and has been proven to be an efficient means to separate biological macromolecules, membranes, cell organelles and cells owing to its advantages such as protecting protein denaturation, easy operation, high efficiency and recovery 11…”