Volatile fatty acids as novel building blocks for oil based chemistry via oleaginous yeasts fermentation.

Microbial oils are proposed as a suitable alternative to petroleum-based chemistry in terms of environment preservation. These oils have traditionally been studied using sugar-based feedstock, which implies high costs, substrate limitation and high contamination risks. In this sense, low-cost carbon sources such as volatile fatty acids (VFAs) are envisaged as promising building blocks for lipid biosynthesis to produce oil-based bioproducts. VFAs can be generated from a wide variety of organic wastes through anaerobic digestion and further converted into lipids by oleaginous yeasts (OY) in a fermentation process. These microorganisms can accumulate, in form of lipid bodies (LB), lipids up to 60 % w/w of their biomass. In this context, OY arise as a promising biotechnological tool for biofuels and bioproducts generation using low-cost VFAs media as substrates. This review covers recent advances in microbial oil production from VFAs. Production of VFAs via anaerobic digestion processes and the involved metabolic pathways are reviewed. Main challenges as well as recent approaches for lipid overproduction are also discussed. This article is protected by copyright. All rights reserved.