Morphology and rheological behaviour of Yarrowia lipolitica during production of intra-cellular energetic molecules: Impact of lipid accumulation and genetic modifications.

In: Proceeding of 8th World Congress of Chemical Engineering, August 23-29, Montréal, Quebec, Canada. Eds. Canadian Society for Chemical Engineering. (Ontario, Canada), ISBN: 0-9208044-44-6, Session: Bioproducts, Bioreactors and Bioprocesses, L.0122, 2009In: Proceeding of 8th World Congress of Chemical Engineering, August 23-29, Montréal, Quebec, Canada. Eds. Canadian Society for Chemical Engineering. (Ontario, Canada), ISBN: 0-9208044-44-6, Session: Bioproducts, Bioreactors and Bioprocesses, L.0122, 2009Efficient microbial conversion of carbohydrates from plant biomass into energetic molecules such as specific lipids is a real challenge in bioprocess. Our study focussed on the evolution of yeast morphology and rheological behaviour of cell broth during production of intra-cellular lipids. Three Yarrowia lipolytica strains (wild and genetically engineered strains) were investigated under controlled fed-batch culture including 3 steps (growth, nitrogen limitation and lipid accumulation). Physical (microscopy, rheology, particle size distribution, concentration) and biological (cell dried matter, lipid content) parameters were simultaneously characterised or quantified. Culture strategy enabled to reach up to 111gCDW/L in biomass and 0.36g/gCDW lipid. Results demonstrate that yeast strains are characterised by different morphologies. Lipid synthesis is a complex and vital metabolism which affects morphology and physical properties. Broth rheology depends on biomass concentration, lipid accumulation and morphology and affects bioprocess performances