Biotransformations pros/cons

In designing a process we have the choice of using the whole organism or specific enzymes isolated from it. As always both options have pro s and cons. Broadly speaking we could say that biosynthetic processes mostly rely on whole cells, whereas biotransformations can be catalysed by whole cells and by enzyme preparations. 

Brandon, E.F., Raap, C.D., Meijerman, I. etal. (2003) An update on in vitro test methods in human hepatic drug biotransformation research pros and cons. Toxicology and Applied Pharmacology, 189 (3), 233-246. 

Birkett DJ, Mackenzie PI, Veronese ME, Miners JO (1993) In vitro approaches can predict human drug metabolism. Trends Pharmacol Sci 14 292-294 Bloomer JC, Boyd HF, Hickey DMB et al. (2001) 1-(Arylpiperazinylamidoalkyl)-pyrimidones Orally Active Inhibitors of Lipoprotein-Associated Phospholipase A2. Bioorg Med Chem Lett 11 1925-1929 Brandon EFA, Raap CD, Meijerman I et al. (2003) An update on in vitro test methods in human hepatic drug biotransformation research pros and cons. Toxicol Applied Pharmacol 189 233-246... 

Table 2.4 Pros and cons of biotransformations according to enzyme types. Source adapted from Faber [145],...

For many oxidation and reduction reactions it is often necessary to make a choice between using a whole-cell system or an isolated enzyme (with the requisite co-factors) for the biotransformation. In this area, factors that influence the choice often are much more complicated than those for hydrolysis reactions. The pros and cons of employing whole cells or partially purified oxidoreductase enzymes have been discussed in Chapter 2, and the salient features are summarized in Table 2.3. While the advantages and disadvantages will not be discussed in detail again, many of the points made earlier will recur in this discussion. 

The physical state of biocatalysts which are used for biotransformations can be very diverse. The final decision as to whether one should use isolated, more-or-less purified enzymes or whole microorganisms - either in a free or immobilized form -depends on many factors, such as ( ) the type of reaction, (ii) whether there are cofactors to be recycled, and (Hi) the scale in which the biotransformation has to be performed. The general pros and cons of using isolated enzymes vs. whole (microbial) cells are outlined in Table 1.2. 

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