Team:Johns Hopkins/Vit/Over

Overview

We demonstrated and characterized the production of pro Vitamin A, beta-carotene, in Saccharomyces cerevisiae, by importing three carotegenic genes from Xanthophyllomyces dendrorhous, namely carotene desaturase, GGPP synthase

, phytoene synthase. The quantification was done via HPLC analysis and spectrophotometric assays over time. We also ran a comparative study of our yeast strains efficiency in dough versus in lab conditions using a novel substrate, dough media plates. We see production of significant amounts of betacarotene from this strain.

We have engineered a strain of saccharomyces cerevisiae to express L-ascorbic acid, or Vitamin C, for use in the baking of bread and brewing of beer. We codon optimized three genes from the Vitamin C pathway of arabidopsis thaliana and made biobrick compatible. These were then constructed denovo and assembled into expression cassettes. We are currently in the process of characterizing the Vitamin C production via HPLC and photospectrometric assays. We also in the process of constructing a combinatorial library of expression cassettes with 11 different strength promoters and terminators and have designed a selection and screening protocol to optimize production.