Carbon and nitrogen sources modulate lipase production in the yeast Yarrowia lipolytica

Abstract

Aims: To analyse the influence of nitrogen and carbon sources on extracellular lipase production by Yarrowia lipolytica-overproducing mutant in order to optimize its production in large-scale bioreactors.

Methods and results: The level of lipase production and LIP2 induction, measured using an LIP2-LacZ reporter gene, were compared for different carbon and nitrogen sources and for different concentrations. The localization of the enzyme during growth was also determined by Western blotting analysis using a six-histidine-tagged lipase.

Significance and impact of the study: Tryptone N1 and oleic acid are the most suitable nitrogen and carbon sources for the production of the extracellular lipase by the Y. lipolytica mutant. Higher levels of lipase production were obtained as the tryptone concentration increased in the culture medium. Such a positive correlation was not observed with oleic acid media where the highest lipolytic productivities were obtained in the presence of low concentration. We also demonstrate that in the presence of oleic acid, lipase is cell-bound during the growth phase before being released in the media.

Conclusions: This work provides a better understanding of the mechanism controlling LIP2 expression and, thus, extracellular lipase production in the yeast Y. lipolytica.