Harvesting of cyanobacterium Arthrospira platensis usmg organic filtration membranes

Separation of micro-organisms from their culture medium is a critical point in many biotechnological and environmental applications. Cross-flow microfiltration and ultrafiltration often appear as suitable processes for this purpose. In this study, I I commercial membranes (from Rhodia-Orelis, Miribel, France) were evaluated for harvesting the cyanobacterium Arthrospira platensis. The relative contributions of different membrane characteristics on the permeation flux and the fouling phenomenon were discussed, especially cut-off, constitutive materials and surface properties (charge, hydrophobicity). According to our results, the ultrafiltration membrane IRIS 3038 (polyacrylonitrile, 40 kDa, neutral and hydrophilic) exhibited the best performance in terms of permeation flux and cleanability. Consequently, this membrane was selected to perform A. platensis harvesting experiments with volume reduction factor up to 10. The general framework of this experimental study is the MELISSA project from European Space Agency (ESA, www.estec.esa.nl/ecls/): 'development of auto-regenerative biological life support systems for men in space', partly based on photosynthetic organisms such as cyanobacteria.