Metabolites recovery from fermentation broths via pressure-driven membrane processes

The production of specific metabolites using microorganism has been promoted and enhanced by two different approaches, such as modification of the metabolic pathways of microorganism and optimization of culture medium conditions to synthesize specific compounds. However, research community is today focused on the development of processes and techniques for a suitable recovery of metabolites from different stages of fermentation. For this purpose, the use of organic solvents has been the most common approach for the recovery of specific target compounds according to the solvent affinity. Additionally, these techniques also require the implementation of unit processes to obtain better recovery rates; it means that solvent extraction methods need the implementation of additional steps to recover the solvents used, which may involve the increase of final costs in the production process. For this reason, researchers have started to consider membrane-based technologies (e.g. microfiltration [MF], ultrafiltration [UF], and nanofiltration [NF]), as an alternative for the recovery of metabolites from fermentation broths. Therefore, the objective of this paper is to provide an overview of the current findings of the recovery of metabolites from fermentation broths by means of pressure-driven membrane processes. Particular attention will be paid to relevant data, analyzing and discussing according to the membrane features, metabolite properties, and some other phenomena that influence in the separation. Moreover, a framework of the application of the MF, UF, and NF processes in solutes recovery is addressed. Finally, some fundamentals of these processes are also given.