Arthrospira platensis CULTURED IN TILAPIA EFFLUENT WITH LOW SALINITY PRODUCES ANTIOXIDANT SULFATED POLYSACCHARIDES

Arthrospira platensis produced in tilapia effluent would yield sulfated polysaccharides (ApSPs). This study analyzed ApSPs by two extraction periods (3 or 24 h) on yield, physical-chemical features and in vitro antioxidant effects. Dehydrated biomass from 10‰ organic system was extracted for ApSPs, with papain, in 100 mM sodium acetate buffer (pH 5)+cysteine/EDTA, both 5 mM. After filtration, ApSPs precipited and washed with alcohol were characterized by electrophoreses in agarose/polyacrylamide gels using known glycosaminoglycans and then ApSPs stained with toluidine blue and combined or not with Stains-All. Infrared structurally evaluated the ApSPs. Antioxidant effects were in vitro assayed by DPPH and total antioxidant capacity (TAC) methods using BHT and ascorbic acid as references. Yields differed no between periods (4.3±1.22-3h, 4.57±0.57%-24h) and molecular analyses revealed spirulan-type ApSPs with regularity in charge/size and functional groups between samples. ApSPs showed, concentration-dependent, effects preponderant by DPPH method than TAC one, with only ̴ 50% reduction (4 mg mL-1) vs. BHT (100% inhibition, 4 mg mL-1). Thus, extraction by 3 h optimized ApSPs from massive cultivation in tilapia salinized effluent.