Harvesting of Arthrospira platensis by flocculation with phytic acid from rice bran

Abstract

Abstract The recovery of algal biomass is one of the critical steps involved in the commercial production of beneficial metabolites from Arthrospira platensis. Efficient and safe harvesting methods that do not sacrifice quality of final product are important for commercial application. Phytic acid (PA) is a natural non-toxic phytochemical widely distributed in plant tissues. Effect of PA from rice bran on the growth, trichome morphology such as spiral number and algal filament length, and harvesting efficiency of A. platensis were investigated. Cells aggregated into large cell flocs after the addition of PA in the medium, and algal spiral number and filament length increased. UV-vis spectra indicated the interactions between PA and algal cells. Adding PA at stationary growth phase is a good strategy for harvesting, since no adverse effect to biomass growth and harvesting efficiency. Harvesting efficiency of 95.69% at 0.5% (v/v) PA was superior to other conventional harvesting methodologies. Abbreviations PA: Phytic acid; PUFAs: Polyunsaturated fatty acids; FAO: Food and Agriculture Organization; γ-PGA: Poly (γ-glutamic acid); CNF: Cellulose nanofibrils; NIES: National Institute for Environmental Studies; SOT: Spirulina–Ogawa–Terui; CG: Control group; pI: Isoelectric point.