Obtaining zinc enriched spirulina biomass and establishing its toxicity

Abstract

The effect of different zinc concentrations in the standard nutrient medium Zarruka on the intensity of Spirulina platensis biomass growth is being stuided. Enrichment of spirulina was made by introducing various concentrations of zinc sulphate – from 6.0 to 24.6 mg/l into standard nutrient medium Zarruka. Adding zinc sulfate in a dose of 6.0 mg/l to the cultivation medium manifests stimulating effect on Spirulina platensis cell growth, and then due to accumulation of metal manifests its toxic effect. Adding high doses of Zinc to the nutrient medium leads to a sharp decrease of Spirulina biomass growth and to cell death from the eighth day. While exploring the acute toxicity of Spirulina platensis biomass, enriched with Zinc at a dose of 5000 mg/kg, by intragastric administration to rats and white mice, there were not observed animal deaths. Clinical response both white mice and rats to Spirulina platensis biomass, enriched with Zinc, was similar. In both cases, even repeated administration of high-dose supplements in the amount of 5000 mg/kg per body weight was not fatal. Under these conditions, the Spirulina biomass in concentrations up to 5000 mg/kg of body weight really matters (DL0).