Biosensor-Enabled Directed Evolution to Improve Muconic Acid Production in Saccharomyces cerevisiae.

Muconic acid is a valuable platform chemical with potential applications in the production of polymers such as nylon and polyethylene terephthalate (PET). The conjugate base, muconate, has been previously biosynthesized in the bacterial host Escherichia coli. Likewise, previous significant pathway engineering lead to the first reported instance of rationally engineered production of muconic acid in the yeast Saccharomyces cerevisiae.

Coordinated transcription factor and promoter engineering to establish strong expression elements in Saccharomyces cerevisiae.

Gene expression requires the coordination of trans-acting factors and cis-DNA elements to initiate transcription. Here we present a coordinated approach that combines cis-acting element engineering with mutant trans-acting factors to engineer yeast promoters. Specifically, we first construct a hybrid promoter based on the ARO9 upstream region that exhibits high constitutive and inducible expression with respect to exogenous tryptophan.

Advances and current limitations in transcript-level control of gene expression.

Gene expression control is critical to increase production of recombinant proteins, fine-tune metabolic pathways and reliably express synthetic pathways. The importance of transcriptional control seems to be most important in eukaryotic systems. In this review, we highlight recent developments in the field of transcriptional engineering with an emphasis on the opportunities and challenges.

Metabolic engineering of muconic acid production in Saccharomyces cerevisiae.

The dicarboxylic acid muconic acid has garnered significant interest due to its potential use as a platform chemical for the production of several valuable consumer bio-plastics including nylon-6,6 and polyurethane (via an adipic acid intermediate) and polyethylene terephthalate (PET) (via a terephthalic acid intermediate). Many process advantages (including lower pH levels) support the production of this molecule in yeast. Here, we present the first heterologous production of muconic acid in the yeast Saccharomyces cerevisiae.

Regulation of the anthocyanin biosynthetic pathway by the TTG1/bHLH/Myb transcriptional complex in Arabidopsis seedlings.

In all higher plants studied to date, the anthocyanin pigment pathway is regulated by a suite of transcription factors that include Myb, bHLH and WD-repeat proteins. However, in Arabidopsis thaliana, the Myb regulators remain to be conclusively identified, and little is known about anthocyanin pathway regulation by TTG1-dependent transcriptional complexes. Previous overexpression of the PAP1 Myb suggested that genes from the entire phenylpropanoid pathway are targets of regulation by Myb/bHLH/WD-repeat complexes in Arabidopsis, in contrast to other plants.