Production of Astaxanthin Using Isoprenoid Pathways in Metabolically Engineered Escherichia coli

Astaxanthin is a reddish keto-carotenoid classified as xanthophyll which could be found in microalgae, yeast, and in some types of seafood. It is 10 to 100 times more powerful antioxidant than other carotenoids like beta-carotene or lycopene. It can be used as food pigment, powerful antioxidant, anticancer applicant and cosmetic compound. Although it has many valuable uses, its yield from natural source is low for meet the increasing demand and because of the stereoisomers, chemical synthesis has low efficiency, too. Therefore the production of astaxanthin in Escherichia coli was conducted in this study. Firstly, the heterogenous genes from Pantoea ananatis were introduced into E. coli for production of beta-carotene, which is an important precursor of astaxanthin. After comparison of different gene expression degrees, downstream genes toward astaxanthin were introduced. After development of base strain, native DXP pathway in E. coli was overexpressed in chromosomal level and heterogenous mevalonate pathway from yeast was introduced for increasing production rate. The strageties for increasing precursor pools of carotenoids such as GGPP and beta-carotene could be applied for further research. [This work was supported by the Technology Development Program to Solve Climate Changes on Systems Metabolic Engineering for Biorefineries from the Ministry of Science, ICT and Future Planning (MSIP) through the National Research Foundation (NRF) of Korea (NRF-2012M1A2A2026556 and NRF-2012M1A2A2026557).]