Membranes for the downstream treating of biotechnology processes

In the downstream of biotechnological processes, membrane technologies can successfully replace many, if not all, conventional separation steps for purification, concentration, and recovery of valuable bioproducts. Membranes have the potential to overcome all the challenges required by separation processes: to reduce the number of steps, time, and cost and to increase both selectivity and productivity without any phase change or interphase transfer. Membranes are simple, flexible, and adaptable in a multitude of configurations to suit different physicochemical properties of complex biological broths. This chapter discusses all possible membrane configurations with their applications in downstream of biotechnological processes, with emphasis on the recovery of volatile fatty acids, which are very explanatory for their wide range of possible characteristics. The major operational limitation for membrane performance and efficiency is fouling. Microfiltration and ultrafiltration systems can pretreat the broth to prevent fouling on the more expensive final filters, but efforts must be made to engineer membranes in order to reduce their intrinsic tendency to fouling and thus promote the industrial application of membranes in downstream processes.