Production of Antioxidants from Microbial biocatalysts

Terpenes, including carotenoids and apo-carotenoids, are the largest class of natural products. Carotenoids are a class of pigmented compounds naturally produced by plants and some fungi and bacteria. Members of carotenoids include lycopene, β-carotene, and astaxanthin. These compounds are antioxidants that have potential positive impact on human health. Carotenoids are used as supplements, food coloring, fortified foods, and cosmetics with market value expected to reach 2 billion by 2022. Apo-carotenoids are oxidative cleavage products of carotenoids, members include alpha-ionone and beta-ionone that contributes to the fragrance of roses and violets. Due to their structural complexity, the traditional chemical synthesis of these compounds is often times challenging, expensive, and uses toxic solvents. Few carotenoids can be produced via chemical synthesis on an industrial scale. Thus, biochemical routes have been explored extensively over the last couple of decades via metabolic engineering and synthetic biology of microbial systems for more efficient production from renewable feedstocks. The overall goal of this project is to produce the apo-carotenoid alpha-ionone using bakers yeast Saccharomyces cerevisiae.

Research Objective:

The objectives of the proposal are: 1) to metabolically engineer an alpha-ionone producing strain of yeast and 2) to develop a teaching module on biotechnology for high school students. We will engineer a strain of bakers yeast Saccharomyces cerevisiae capable of converting glucose to a high-value fragrance compound, alpha-ionone. Lycopene is a pre-cursor for alpha-ionone, and we already have a lycopene hyperproducing strain, which will serve as the starting point for the metabolic engineering.