Economic Viability of Phenylalanine Production by Synechococcus elongatus 11801

Phenylalanine (Phe) is an essential amino acid that has uses in the feed, food and pharmaceutical industries. There is a large and growing market for Phe as a precursor to the production of artificial sweetener. Industrially, Phe is produced by feeding glucose to genetically modified strains of heterotrophic organisms such as E. coli or Corynebacterium in a stainless-steel fermenter. Cyanobacteria are photosynthetic microalgae which could replace heterotrophic production thereby reducing land use for crops required for glucose production. SYN-PHE, a strain of Synechococcus elongatus sp. PCC 11801 which was previously developed in the Morgan lab at Purdue University, produces Phe at 1 g/L in 3 days in shake flask cultures. In this thesis, a techno-economic analysis of Phe production by E. coli and SYN-PHE were compared. Results indicate that Phe produced by SYN-PHE is a promising competitor of E. coli produced Phe at an industrial scale. Further strain engineering to improve the titer of Phe is needed to be economically competitive. Additionally, efforts are needed for low capital cost photobioreactors that can enable both high biomass concentrations and high Phe titers.