Non-disruptive sonication of A. fusiformis (A. platensis) cultures facilitates its harvesting

The cyanobacterium Arthrospira fusiformis (also called Arthrospira platensis) is commercially produced as a human dietary supplement as well as a feed supplement for the poultry and aquaculture industries. Due to the relatively dilute nature of the cultures, cost effective means of cell separation are needed. In this short note we present the use of ultrasounds for buoyancy elimination in A. fusiformis without affecting either its viability or breaking its typical multicellular spiral morphology. We also show how after a non-disruptive sonication treatment, these microalgae can be easily settled thus concentrating the biomass about 30-fold while achieving recovery yields of around 80-85%.