The shear stress of microalgal cell suspensions (Tetraselmis suecica) in tangential flow filtration systems: the role of pumps

A widely used technique for cell harvesting is crossflow microfiltration. T he relative fragility of microalgae requires choosing a suitable pumping sy stem. Tetraselmis suecica, which is a very mobile alga, is an interesting m odel for this study. The extent of damage observed in various pumps was mea sured as a function of the number of passes of the algal suspension through the pumps in a closed loop. A loss of microalgal motility could occur with either centrifugal or rotary vane positive displacement pumps. On the cont rary, electronic microscope observation revealed that, during concentration using an eccentric rotor pump or a peristaltic pump, microalgae were not d amaged. (C) 1998 Elsevier Science Ltd. All rights reserved.