Arthrospira platensis CULTURED IN TILAPIA EFFLUENT WITH LOW SALINITY PRODUCES ANTIOXIDANT SULFATED POLYSACCHARIDES
DOI:
https://doi.org/10.18817/repesca.v15i1.3600Resumo
Arthrospira platensis is a cyanobacterium that tolarates environmental fluctuations and its production in tilapia effluent (pH 10/10‰ salinity) 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. Fresh biomass, produced in tilapia effluent using fiber boxes, was dehydrated for ApSPs extraction with papain, in 100 mM sodium acetate buffer (pH 5) + cysteine/EDTA, both 5 mM. After filtration, ApSPs were precipited with 92.8% cold alcohol, followed by alcoholic washings. Electrophoreses in agarose/polyacrylamide gels were performed using known glycosaminoglycans and then ApSPs stained with toluidine blue and combined or not with Stains-All. Infrared spectroscopy structurally evaluated the ApSPs. Antioxidant effects were in vitro assayed by DPPH and total antioxidant capacity (TAC) methods using BHT and ascorbic acid as standards. Yields differed no between periods (4.3 ± 1.22-3h, 4.57 ± 0.57%-24h) and molecular analyses revealed spirulan-type ApSPs rich in uronic acids 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 at 4 mg mL-1 vs. BHT (100% inhibition, 4 mg mL-1). Thus, extraction by 3 h optimized ApSPs from a massive cultivation of this cyanobacterium in organic medium.