Microbial and enzymatic strategies for the production of L-ribose.

L-Ribose is a non-naturally occurring pentose that recently has become known for its potential application in the pharmaceutical industry, as it is an ideal starting material for use in synthesizing L-nucleosides analogues, an important class of antiviral drugs. In the past few decades, the synthesis of L-ribose has been mainly undertaken through the chemical route. However, chemical synthesis of L-ribose is difficult to achieve on an industrial scale. Therefore, the biotechnological production of L-ribose has gained considerable attention, as it exhibits many merits over the chemical approaches. The present review focuses on various biotechnological strategies for the production of L-ribose through microbial biotransformation and enzymatic catalysis, and in particular on an analysis and comparison of the synthetic methods and different enzymes. The physiological functions and applications of L-ribose are also elucidated. In addition, different sugar isomerases involved in the production of L-ribose from a number of sources are discussed in detail with regard to their biochemical properties. Furthermore, analysis of the separation issues of L-ribose from the reaction solution and different purification methods is presented.Key points • l -Arabinose, l -ribulose and ribitol can be used to produce l -ribose by enzymes. • Five enzymes are systematically introduced for production of l -ribose. • Microbial transformation and enzymatic methods are promising for yielding l -ribose.