State-of-the-art in the accumulation of lipids and other bioproducts from sustainable sources by Yarrowia lipolytica

Energy and environmental issues related to conventional fossil-derived products and fuels have led researchers to focus on alternative, more environmentally-friendly processes, such as the production of microbial oils from renewable feedstocks or even pollutants as sustainable sources of biofuels, allowing to progressively move away from the use of fossil fuels. Among the oleaginous yeasts, Yarrowia lipolytica is a highly promising cell factory and microbial oil producer because of its high capacity to accumulate lipids for subsequent biofuel production. Y. lipolytica also stands out for its ability to assimilate various carbon sources, even at low cost, reaching lipid concentrations of at least 30% by weight with non-genetically modified strains, and even much higher values with engineered organisms. Among others, fatty acids have attracted recent interest as substrates for their lower cost and possible production from pollutants compared to sugars. This review pays special attention to some of those emerging carbon sources, i.e., carboxylic acids and even greenhouse gases. Besides, another focus is to provide detailed up to date information on the main characteristics and factors that most influence the fermentation process of this yeast, with the ultimate aim of optimising the bioconversion process and the synthesis of useful metabolites. Besides, the reader will find comprehensive information on the industrial applicability of the synthesised lipids, in addition to the production of biofuels. Apart from lipids, other metabolites of interest that can be synthesised by Y. lipolytica are also discussed.