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Volume 7, Issue 6 (Suppl) J Bacteriol Parasito
ISSN: 2155-9597 JBP, an open access journal Microbiology 2016
November 28-29, 2016
November 28-29, 2016 Valencia, Spain
7th World Congress on
Microbiology
The pPOX2 and pLIP2 regulation in response to carbon source in the yeast Yarrowia lipolytica
Patrick Fickers1, Hosni Sassi3, Jean-Marc Nicaud2, Anne-Marie Crutz-Le Coq2 and Frank Delvigne1
1University of Liege, Belgium
2Institut Micalis, France
3Université libre de Bruxelles, Belgium
The non-conventional yeast Yarrowia lipolytica has been extensively used to produce recombinant proteins for various
biotechnological applications. Actually, more than 110 proteins from human, plants and bacterial systems have been successfully
expressed and produced in Yarrowia lipolytica. However, understanding the regulation of the promoters used to drive heterologous
gene expression is a key parameter in the development of an efficient process. In this study, the regulation of the promoter of acycl-
CoA oxidase gene 2 (pPOX2) and of the extracellular lipase 2 (pLIP2) were considered in regard to the medium composition and to
the carbon source used (glucose, glycerol, oleic acid). Induction levels of promoters were measured using a reporter system based
on a red fluorescent protein (DsRed). Specific fluorescence measurement revealed that pLIP2 is more strongly induced than pPOX2 ,
especially in complex medium. Interestingly, higher levels of induction were obtained when a combination of glucose and oleic acid
was used as carbon source compared to an oleic acid based medium. In order to define the optimal ratio of glucose/oleic acid to be
used, several ratios of carbon sources have been tested for their induction potential. A high induction level of pLIP2 was obtained
when oleic acid fraction in the culture medium was in the range of 0.6-0.9 cmol. Interestingly, relative fluorescence was increased
slightly in this range by a factor of 18% compared to the use of 100% oleic acid. This result suggests that glucose can be considered as
the most promising co-substrate to enhance recombinant protein production under pLIP2. Nonetheless, glycerol can replace partially
oleic acid to express heterologous protein under pPOX2. Thus, the use of glycerol permits to lower the process cost but it also opens
new perspectives for glycerol based microbiological processes. In conclusion, this work provides alternative strategies to enhance
heterologous protein production in Yarrowia lipolytica which increase its interest as a promising recombinant expression system.
J Bacteriol Parasitol 2016, 7:6 (Suppl)