Biotransformation by isolated enzymes
Isolated enzymes typically have higher biotransformation rates than cell
culture-based methods. But the cost of isolating the enzyme plays an
important role in using that enzyme to produce volatiles [144].
Enzymes have a high selectivity and minimize the production of
undesirable by-products [145]. However, most studies have been done
by whole-cells systems rather than isolated enzymes (7%) [146].
Although this method has been significant extent [147], but only in
cases of biological transmission, volatiles are present. The use of
isolated enzymes for biotransformation depends on the availability of
the enzyme for the desired conversion reaction, pH, optimum temperature
conditions, solvent and substrate. The nature of the enzyme, the type of
biotransformation reaction and the need for a cofactor are the
determining factors of the method of using the enzyme. In order to
facilitate the separation of the product and the catalyst recycling, the
use of immobilizing the enzyme is preferred [148].
The table 7 and 8 present a list of some of the volatile compounds
produced by biotransformation of plant cultures, microorganisms and
isolated enzymes.