Development of an Ene Reductase-Based Biocatalytic Process for the Production of Flavor Compounds

• Published in: Organic process research & development 2022-07, Vol.26 (7), p.2102-2110
• Main Authors: Papadopoulou, Athena, Peters, Christin, Borchert, Sonja, Steiner, Kerstin, Buller, Rebecca
• Format: Article
• Language: English
• ISSN: 1083-6160; 1520-586X
• DOI: 10.1021/acs.oprd.2c00096

Ene reductases catalyze the biocatalytic reduction of activated alkenes, offering a powerful biobased alternative to metal-catalyzed and organocatalyzed double-bond reductions. With the aim to utilize the natural catalysts for the development of sustainable industrial processes for the flavor and fragrance (F&F) industry, we investigated the synthetic potential of a wild-type ene reductase library consisting of 20 enzymes to produce flavor compounds, including decanal. In our library screening, we identified several ene reductases that could efficiently reduce 2E-decenal as well as other investigated target substrates. Five of the characterized enzymes exhibited high reduction activities even at increased substrate concentrations (10 g/L). By analyzing additional enzyme characteristics (thermostability, solubility, and activity at 10 °C), enzyme Pbr-ER from Pseudomonas brassicacearum was chosen for further characterization and process optimization. Using optimized reaction conditions, the Pbr-ER-catalyzed reduction of 2E-decenal was performed at 100 mL scale at 40 g/L substrate concentration, achieving a high conversion yield (>93%) within 24 h.