Yarrowia lipolytica produces lipid-rich biomass in medium mimicking lignocellulosic biomass hydrolysate.

In recent years, lignocellulosic biomass has become an attractive low-cost raw material for microbial bioprocesses aiming the production of biofuels and other valuable chemicals. However, these feedstocks require preliminary pretreatments to increase their utilization by microorganisms, which may lead to the formation of various compounds (acetic acid, formic acid, furfural, 5-hydroxymethylfurfural, p-coumaric acid, vanillin, or benzoic acid) with antimicrobial activity. Batch cultures in microplate wells demonstrated the ability of Yarrowia strains (three of Y. lipolytica and one of Y. divulgata) to grow in media containing each one of these compounds. Cellular growth of Yarrowia lipolytica W29 and NCYC 2904 (chosen strains) was proven in Erlenmeyer flasks and bioreactor experiments where an accumulation of intracellular lipids was also observed in culture medium mimicking lignocellulosic biomass hydrolysate containing glucose, xylose, acetic acid, formic acid, furfural, and 5-HMF. Lipid contents of 35% (w/w) and 42% (w/w) were obtained in bioreactor batch cultures with Y. lipolytica W29 and NCYC 2904, respectively, showing the potential of this oleaginous yeast to use lignocellulosic biomass hydrolysates as feedstock for obtaining valuable compounds, such as microbial lipids that have many industrial applications. KEY POINTS: • Yarrowia strains tolerate compounds found in lignocellulosic biomass hydrolysate • Y. lipolytica consumed compounds found in lignocellulosic biomass hydrolysate • 42% (w/w) of microbial lipids was attained in bioreactor batch cultures.