Developing an objective function to characterize the tradeoffs in salting out and the foam and droplet fractionation processes

Abstract

There are many methods for separating and purifying proteins from dilute solutions, such as salting out/precipitation, adsorption/chromatography, foam fractionation, and droplet fractionation. In order to determine the optimal condition for a selected separation and purification process, an objective function is developed. The objective function consists of three parameters, which are the protein mass recovery, the separation ratio, and the enzymatic activity ratio. In this paper the objective function is determined as a function of the pH of the bulk solution for egg albumin, cellulase, and sporamin (for foam fractionation) and invertase ( for droplet fractionation). It is found that the optimal pH for all the systems except for cellulase is near their isoelectric point

Development of Activity-based Cost Functions for Cellulase, Invertase, and Other Enzymes

“…We shall start with a more generalized objective function comprised of measurable purification process responses to create our cost model and reduce that model to the specific cost function for this study. A previously developed objective function quantifies the tradeoff between maximizing the enzyme concentration in a separation process such as a foam fractionation process and minimizing the loss of enzyme mass and enzyme activity in that process [1] is shown below.…”

“…In a foam-fractionation process, in particular, these control parameters are typically the pH and the foaming-gas superficial velocity [1]. In this approach, it is convenient to define Φ as a generalized value (or price) function.…”