High-yield Biosynthesis of Protocatechuate Through Fine Tuning of Biosynthetic Pathway

다국어 초록 (Multilingual Abstract)

Protocatechuate (PCA) is promising building block for synthesizing polymer and plastics. It also has pharmaceutical activities. PCA is naturally present in many plants, but it is impractical to directly extract from natural resources due to low yields. Many efforts have been made over the past years to produce PCA from microbial strains (1), but previous studies either create auxotrophic strain or lack a sufficiently diverse and precise regulation gene expression involved in PCA biosynthesis. We demonstrated an efficient production method via precise tuning of gene expression that related to PCA biosynthesis in E. coli. We used qsuB and precisely controlled the expression level using tunable gene regulation system (2). To decrease precursor consumption, the expression levels of aroE and ydiB, involved in shikimate pathway, were modulated by synthetic sRNAs with different strength (3). Furthermore, several gene modules containing enzymes involved in shikimate pathway and expected to increase the intracellular production of PCA were overexpressed.