Recovery and valorization of agri-food wastes and by-products using the non-conventional yeast Yarrowia lipolytica

Background: Yarrowia lipolytica is one of the most studied “non-conventional” yeasts. Due to its intrinsic biological characteristics and variability, the potential applications of wild type isolates in the agri-food sector are broad (production of biomasses, enzymes, and metabolites). By-products generated by the food industry are rising environmental and economic concerns worldwide. These side streams have different compositions and stability. However, they can still be applied as substrates for microbial growth. Scope and approach: The fitness of wild type strains to adverse and different environments can be exploited not only for food production but also for recovery and valorization of agri-food wastes and by-products. This review brings together a selection of the most relevant and recent data about the physiology, nutritional requirements, and metabolites produced by wild type isolates of Y. lipolytica. Moreover, the principal agri-food side streams, their specific productions and valorization using wild type strains have been critically discussed. Key finding and conclusions: Critical aspects of side streams and by-products can be solved (e.g. reduction of COD and pollutants before discharging), novel ingredients can be generated (e.g. lipases, single cell oils and citric acid) and, eventually, yeast biomasses can be produced for further applications (food adjuncts or supplements). Selecting and characterizing wild type isolates able to consume or convert or valorize the different waste/by-product components into added value products is extremely important in the view of a sustainable process and sustainable economy.