Current Synthetic and Systems Biology
Open Access

Using promoter architecture to guide engineering the strongest known fatty acid inducible hybrid promoter in Yarrowia lipolytica

3^rd International Conference on Systems and Synthetic Biology

July 20-21, 2017 Munich, Germany

Murtaza Shabbir Hussain, Ian Wheeldon and Mark A Blenner

Clemson University, USA
University of California, USA

Posters & Accepted Abstracts: Curr Synthetic Sys Biol

Abstract :

Recently, there have been significant improvements in the genetic toolbox for the industrial oleaginous microbe, Y. lipolytica. These tools range from CRISPR-Cas9 mediated genome editing to libraries of hybrid promoters made from strong upstream activating sequences for tunable strength; however, strong inducible promoters remain undeveloped. In addition to tunable strength, having control of timing of gene expression can improve cellular efficiency by separating the growth and production phase. Inducible regulation is particularly important when certain chemicals produced could be toxic and inhibit growth, or when requiring the ability to switch on production at stationary phase. Here, we demonstrate the development of the only known and strongest fatty acid inducible promoter system in Y. lipolytica. The hybrid promoter has nearly 50-fold induction strength relative to glucose with expression ranging from 2 to 10-fold higher than the commonly used native inducible acyl CoA oxidase promoter. We show that this range of tunable induction strengths can be accomplished by different functional elements comprising the hybrid promoter. While repressed in the absence of fatty acids, the hybrid promoter lacks catabolite repression in the presence of either glucose or glycerol in fatty acid containing media. Furthermore, this inducible genetic switch can be strongly activated at stationary phase with low concentrations of a wide range of fatty acids ranging from oleic acid to eicosapentaenoic acid. The hybrid promoter activity correlates well with changes in intracellular fatty acid pools, suggesting its use as a tool for strain engineering.

Biography :

Email: mshabbi@g.clemson.edu