Dwindling petroleum feedstocks and increased CO2-concentrations in the atmosphere currently open the concept of using CO2 as raw material for the synthesis of well-defined organic compounds. In parallel to recent advances in the chemical CO2-fixation, enzymatic (biocatalytic) carboxylation is currently being investigated at an increased pace. On the one hand, this critical review provides a concise overview on highly specific biosynthetic pathways for CO2-fixation and, on the other hand, a summary of biodegradation (detoxification) processes involving enzymes which possess relaxed substrate specificities, which allow their application for the regioselective carboxylation of organic substrates to furnish the corresponding carboxylic acids (145 references).
