Volatile fatty acids as novel building blocks for oil‐based chemistry via oleaginous yeast fermentation

Abstract

Microbial oils are proposed as a suitable alternative to petroleum‐based chemistry in terms of environmental 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 (OYs) in a fermentation process. These microorganisms can accumulate in the form of lipid bodies, lipids of up to 60% wt/wt of their biomass. In this context, OY is a promising biotechnological tool for biofuel and bioproduct generation using low‐cost VFA 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. The main challenges as well as recent approaches for lipid overproduction are also discussed.

Parametric optimization and kinetic study of l‐lactic acid production by homologous batch fermentation of Lactobacillus pentosus cells

“…When the fermentation temperature was relatively low and close to the optimum temperature for cell growth, the substrate was mainly consumed for cell growth instead of being utilized for product synthesis, resulting in a decrease in product yield and productivity. When the fermentation temperature was higher than the optimal temperature for product synthesis, the biomass concentration was further reduced, and the activity of the enzyme for product synthesis was inhibited, which led to a reduction in the fermentation efficiency [22]. Excessively low (<27 °C) or high temperature (>39 °C) would inhibit the activity of enzymes in cells, and massive cell death would be caused by extremely high (>43 °C) temperature, which would have a significant negative impact on the fermentation efficiency [23].…”

Engineering precursor pools for increasing production of odd-chain fatty acids inYarrowia lipolytica

“…Acetate as well as propionate, substrates used in this study, are major components of volatile fatty acids (VFAs) being easily obtainable from agro-industrial wastes or biodegradable organic wastes. VFAs as a substrate for microbial oil production has recently been gaining a lot of interest due to its low cost [Liu et al 2017; Llamas et al 2019]. Thus, the utilization of VFAs for the production of OCFAs in Y. lipolytica will be a feasible and sustainable strategy for the scale-up process.…”

Microalgae Biomass as a Potential Feedstock for the Carboxylate Platform

“…Finally, VFAs are regarded as low-cost carbon sources for lipid biosynthesis to produce oil-based products [72]. Oleaginous yeasts such as Yarrowia Lipolytica or Cryptococcus Curvatus can accumulate up to 60% of their dry weight in the form of lipid bodies [73].…”