MEEC-technique

For small-scale synthesis enclosure of enzymes in dialysis tubes has been described for several systems (membrane-enclosed enzyme catalysis or the MEEC technique 127 ). In this case mass transport of the low-molecular-weight substrates and products across the membrane becomes rate limiting because mass transport only occurs by diffusion and not by convection as described below. 

Pyruvate kinases are commercially available from multiple sources1381. The enzyme generally used in ATP regeneration - from rabbit muscle - has high specific activity (-500 U per mg of protein), is inexpensive ( 2-4/1000 U), and is stable when immobilized165-671. This regeneration system can be used in membrane enclosed enzyme catalysis (MEEC technique)[68, 691 as well. 

Fig. 3.7 Principle of a membrane reactor and the membrane-enclosed enz3nne catalysis (MEEC)-technique...

A simplified form of a membrane reactor which does not require any special equipment may be obtained by using an enzyme solution enclosed in dialysis tubing like a tea bag (Fig. 3.7). This simple technique termed membrane-enclosed enzymatic catalysis (MEEC) seems to be applicable to most types of enzymes except lipases [447 149]. It consists of a dialysis bag containing the enzyme solution, mounted on a gently rotating magnetic stirring bar. 

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