Enzymatic Kolbe-Schmitt Reaction for the Syntheses of Value-Added Compounds: Use of Biocatalysts for Carboxylation of Organic Compounds and Bioproduction. Use of Biocatalysts for Carboxylation of Organic Compounds and Bioproduction.

Biocatalytic reactions by enzymes have become significant for bioproduction of value-added compounds since they enable selective production of the desired compounds due to reaction-, substrate- and regio-specific enzymatic activities. In this review, the enzymatic carboxylation reactions applicable to bioproduction of aryl hydroxycarboxylic acids are discussed. Especially, the reversible decarboxylases found in microorganisms are important for bioproduction. These enzymes catalyze reverse reaction, regio-specific carboxylation, without coenzymes or ATP, and are applicable to direct carboxylation of specific compounds in solutions containing KHCO₃ or NaHCO₃. Salicylate decarboxylase (EC 4.1.1.91) is one of the key reversible decarboxylases, catalyzing the synthesis of salicylic acid from phenol, by the enzymatic Kolbe-Schmitt reaction. The possible applications of the enzymatic Kolbe-Schmitt reaction and the future direction of this research field are discussed.