Biosorbtion, localization and bioavailability of zinc in Spirulina platensis culture

Abstract

A study of Spirulina platensis taking up Zn was conducted in modified culture media with various Zn salts. Spirulina platensis cultured for 7 days in modified Zarrouk’s medium 1.6 µmol Zn of ZnSO4 (MZS) contained the highest Zn content. The MZS were 69.55±2.70 µg/g dry weight for Zn concentration, 63.11±1.40 %db for protein content, 0.46 day-1 for specific growth rate (µ), 0.55 g/L.day dry weight cell for productivity (Px), and 1.50 days for doubling time (td). The majority of Zn deposit was in the cytoplasm which was 2.7-fold higher than that in the cell walls. Fourier transform infrared (FTIR) spectra showed the decreasing of peak intensity for the amide groups after Zn uptake which indicated their important role in the binding of Zn. The simulated digestion in gastric and intestinal tracks of S. platensis cells cultured in MZS cells was the accessibility of 55.20±0.57 and 63.55±0.21%, respectively. After sequentially gastric and intestinal digestion, the Zn availability was 34.63±0.95%.