Two novel cyanobacterial α-dioxygenases for the biosynthesis of fatty aldehydes

• Published in: Applied microbiology and biotechnology 2022-01, Vol.106 (1), p.197-210
• Main Authors: Kim, In Jung, Brack, Yannik, Bayer, Thomas, Bornscheuer, Uwe T.
• Format: Article
• Language: English
• Subjects: Aldehydes; Aroma compounds; Biomedical and Life Sciences; Biosynthesis; Biotechnologically Relevant Enzymes and Proteins; Biotechnology; Cyanobacteria; Dioxygenases; E coli; Enzymes; Escherichia coli; Escherichia coli - genetics; Fatty Acids; Flavor compounds; Heme; Life Sciences; Microbial Genetics and Genomics; Microbiology; Oxidation
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-021-11724-x

α-Dioxygenases (α-DOXs) are known as plant enzymes involved in the α-oxidation of fatty acids through which fatty aldehydes, with a high commercial value as flavor and fragrance compounds, are synthesized as products. Currently, little is known about α-DOXs from non-plant organisms. The phylogenic analysis reported here identified a substantial number of α-DOX enzymes across various taxa. Here, we report the functional characterization and Escherichia coli whole-cell application of two novel α-DOXs identified from cyanobacteria: CalDOX from Calothrix parietina and LepDOX from Leptolyngbya sp. The catalytic behavior of the recombinantly expressed CalDOX and LepDOX revealed that they are heme-dependent like plant α-DOXs but exhibit activities toward medium carbon fatty acids ranging from C10 to C14 unlike plant α-DOXs. The in-depth molecular investigation of cyanobacterial α-DOXs and their application in an E. coli whole system employed in this study is useful not only for the understanding of the molecular function of α-DOXs, but also for their industrial utilization in fatty aldehyde biosynthesis. Key points • Two novel α-dioxygenases from Cyanobacteria are reported • Both enzymes prefer medium-chain fatty acids • Both enzymes are useful for fatty aldehyde biosynthesis Graphical abstract