Microbial oils arises as a promising alternative to petroleum for the production of fuels and chemicals. One of the main advantages of microbial oils is that they can be obtained from renewable sources via oleaginous fermentation. So far, most studies on lipid production via oleaginous yeasts have been carried out using sugars as carbon source. However, due to their high production cost, considerable efforts have been directed towards finding new alternative sources such as organic wastes. Volatile fatty acids can be considered low-cost substrates for yeasts cultivation since they can be generated from a wide variety of organic wastes through anaerobic fermentation. Some microorganisms are able to metabolize these acids and further convert them into lipids in a fermentation process. These microorganisms can accumulate huge amount of lipids reaching up to 60% of their biomass.
Thus, in a first step volatile fatty acid are produced from organic wastes and in a second step, these acids will be utilized as carbon source for the yeast to produce oils. Henceforth, the integration of these two fermentative bioprocesses allows the valorisation of residues and the reduction of associated operational costs, while increasing the revenues coming from the production of high value chemicals for the oleochemical industry.
This review* mainly covers recent advances related to the microbial oil production from volatile fatty acids. More specifically, volatile fatty acids production via anaerobic fermentation processes and the involved metabolic pathways in which they are uptaken by yeast are reviewed. Additionally, the main challenges and recent approaches for lipid overproduction are also discussed.
(*) Llamas M.; Magdalena J.A.; González-Fernández C.; Tomás-Pejó, E.; “Volatile fatty acids as novel building blocks for oil-based chemistry via oleaginous fermentation”. Biotechnology and Bioengineering (2019)1-13. DOI: 10.1002/bit.27180
More information: Cristina González, Head of the Biotechnological Processes Unit firstname.lastname@example.org