Whole-cell biocatalysts disadvantage

Table 1-7. Advantages and disadvantages using isolated enzymes or whole cell biocatalysts.

During the last decade, significant advancements in biochemistry, molecular cloning, and random and site-directed mutagenesis, directed evolution of biocatalysts, metabolic engineering and fermentation technology have led us to devise methods to circumvent the disadvantages of whole-cell biotransformation discussed in Section 10.2. The applications of these methods are summarized in this section. 

In general there are two principle possibilities using a biocatalyst in organic synthesis, namely as whole cells or as isolated enzymes - free or immobilized. The advantages and disadvantages of each can be intensively discussed, but the outcome of this consideration always depends on the whole system and the kind of application. There are numerous examples of both and thus there is no partitioning between whole cell biotransformation and isolated enzymes in this review. 

Describe in your own words the advantages and disadvantages of using whole cells compared to isolated enzymes as biocatalysts, with respect to catalyst immobilization, catalyst recovery, ease of use, and product selectivity and purification. 

Figure 15-21. Advantages and disadvantages of whole cell, isolated enzymes and recombinant cell as biocatalysts.

Cofactor recycling is no problem when whole microbial cells are used as biocatalysts for redox reactions. In this case, inexpensive sources of redox equivalents such as carbohydrates can be used since the microorganism possesses all the enzymes and cofactors which are required for metabolism. The advantages and disadvantages of using whole-cell systems are discussed in Sect. 2.2.3. 

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