Acidogenesis and chain elongation for bioproduct development

Abstract Transition into a circular economy based on sustainable use of resources is, nowadays, a main. For this purpose, waste streams constitute a cost-effective raw material from which volatile fatty acids (VFAs) can be obtained through anaerobic digestion (AD). This review is aimed at providing useful information about different aspects involving VFA production (acidogenesis), as well as the main technologies for their separation and purification. Operational conditions, such as pH, hydraulic retention time, organic loading rate, temperature, and different pretreatments applied to the inocula to enhance VFA production, are reported. Microorganisms involved in each stage of the AD are also reviewed. Advantages and disadvantages of existing technologies to separate and purify VFAs are discussed. Finally, the chain elongation production platform is assessed as a tool to obtain medium carbon chain acids, which have a higher market value than short-chain carboxylic acids.