Microbial Production of Capsaicinoids

Capsacinoids are the substances responsible for the pungent sensation of the chili pepper (Capsicum spp.). Capsaicin, 8-methyl-N-vanillyl-trans-6-nonenamide, and dihydrocapsaicin, 8-methyl-N-vanillylnonanamide, are the two major capsaicinoids, responsible for up to 90% of the pungency. In addition to be mainly used as food additives for hot and spicy flavor, capsaicinoids have many pharmaceutical and medical uses.

The demand in the international market for the capsaicinoids, especially capsaicin showed an increasing trend in recent years. However, the content of capsaicinoids in hot peppers is generally very low and affected by environmental and growth conditions. Genetically engineered microbes have become an increasingly important platform for the production of drugs, chemicals, and biofuels from renewable resources. These biotechnological products, when used in food, can be labeled ‘natural’ in food sector according to current regulations.

In this project, based on the analysis of RNAseq and RT-PCR data, we have identified the candidate genes for the enzymes in capsaicin biosynthetic pathway. We have successfully reconstituted the capsaicinoid biosynthetic pathway in E. coli for biotechnological production of various capsaicinoids. The optimization and scale-up of this process are in progress.