Date of Award

Spring 1981

Document Type

Dissertation

Degree Name

Doctor of Engineering Science in Chemical Engineering

Department

Chemical Engineering and Chemistry

First Advisor

Hung T. Chen

Second Advisor

John E. McCormick

Third Advisor

Gordon Lewandowski

Fourth Advisor

Teddy Greenstein

Fifth Advisor

George Y. Lei

Sixth Advisor

Leonard Salzarulo

Abstract

The work on separation and purification of proteins by parametric pumping has been restricted so far to pH parametric pumping where the difference between the iso-electric points of the components to be separated is apparent. The present work establishes the foundations for the continuous separation and purification of proteins (including enzyms) that have similar or very close iso-electric points by using the ionic strength as a driving force for the separation process. This technique has commercial advantages over batch processes.

It was found that the most promising technique for separating alkaline phosphatase consists of the following three major steps: (I) addition and binding of all proteins in the mixture at pH 7.4 and ionic strength 0.1, (II) selective desorption of the desired enzyme at pH 7.4 and ionic strength 0.6 and (III) regeneration of the ion exchanger at pH 4.0 and ionic strength 0.1. Several factors were found to affect the purification process, including buffer pH and ionic strength, flow rate, reservoir displacement, feed concentration, product flow rate, type of adsorbent and circulation rate. It is also shown that the technique presented here can yield a larger enzyme activity recovered with high purification factor compared with the conventional adsorption process.

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