Nucleosides constitute an extensive group of natural and chemically modified compounds that
display a wide range of structures and activities. Different biocatalysts have been developed for their preparation,
but the choice of commercially available enzymes is limited. Therefore, the search of new biocatalysts is particularly
attractive. In this sense, microorganisms are a vast source of enzymatic diversity that can be directly used as
whole cell biocatalysts providing a potential cheaper and suitable route for industrial applications.
Methods: This work makes particular emphasis on the following methods: the biocatalyzed whole cell synthesis
of nucleosides mediated by phosphorylases, key biocatalyzed steps involved in other chemoenzymatic routes to
prepare nucleoside analogues and the transformation of nucleosides in derivatives with particular properties.
Results: The literature covered in this work confirms that biocatalytic procedures that make use of whole cell
systems can be successfully applied to obtain a wide variety of nucleoside analogues and their derivatives, providing
alternative and complementary routes to traditional chemistry. The direct use of microbial whole cells as
biocatalysts affords competitive results since it avoids the cumbersome procedures involved in enzyme isolation
and facilitates multienzymatic processes. These biocatalysts also maintain the enzymes in their natural environment,
protecting their activities from reaction conditions.
Conclusion: Although the information presented herein shows that these methodologies have reached a high
degree of development, it is expected that future contributions of protein engineering and nucleoside metabolism
knowledge, among other disciplines, will expand the already wide range of applications in nucleoside chemistry
of whole cell biocatalysis.