Journal of Bacteriology & Parasitology

Novel strategies for the development of heterologous protein production processes based on the pPOX2 promoter in the yeast Yarrowia lipolytica

2^nd International Congress on Bacteriology & Infectious Diseases

November 17-19, 2014 DoubleTree by Hilton Hotel Chicago-North Shore, USA

Hosni Sassi and Patrick Fickers

Posters: J Bacteriol Parasitol

Abstract:

The non-conventional yeast Yarrowia lipolytica has recived much attention as a potential host for heterologous protein productionwith both academic and commercial applications. To this end, the selection of strong and tightly regulated promoters together with the optimisation of heterologous gene expression is essential for the production of pharmaceucals at industrial scale. High heterologous protein production in response of carbon source uptake is of great interest. In this work, the promoter of acycl-CoA oxidase gene 2 (pPOX2) was studied in regard with its regulation during cell growth on complex and defined medium supplemented with different carbon sources. Throught a different combinations of carbone sources, we aimed to define and select the best medium and carbon source for hight level of heterologous protein expression in this yeast. For this purpose, pPOX2 was fused with a reporter gene coding for a red fluorescence protein (DsRed). Measurement of normalized fluorescence level revealed that pPOX2 is strongly induced during growth on medium containing oleic acid as sole carbon source or in combination with glucose or glycerol. Moreover, complex medium appears as the most preferred one. Nevertheless, this promoter is repressed when glucose or glycerol were using as the sole carbon source. This result suggests that oleic acid is a very strong inducer of pPOX2. Furthermore, the use of glycerol in combination with oleic acid let to the same amount of fluorescence level in both complex and defined medium. This research elucidates the effect of different carbon source on gene expression under pPOX2control. Indeed, the use of glycerol as carbon source offers not only a low cost bioprocess but it also open new perspectives for glycerol based microbiological processes. This work provides an alternative strategy to maximize heterologous protein production in Y. lipolytica with the consequence of an increased interest in this yeast as a host for heterologous protein production.