Chromium Interaction with Blue-Green Microalga Spirulina platensis

The interaction of different chromium species with blue-green microalga Spirulina platensis was studied by neutron activation analysis (NAA). It was found that, in contrast to other microorganisms, spirulina predominantly assimilates nontoxic, essential Cr(III) species rather than the toxic Cr(VI) species. Photometry and EPR proved the absence of toxic chromium species with high degrees of oxidation in the course of Cr(III) accumulation by S. platensis cells. The relationship between the Cr(III) concentration in the chromium-containing spirulina biomass and the chromium concentration in the nutrient medium was found; it can be used for the determination of Cr(III) concentrations necessary for cell cultivation. The control of the protein composition and cytological status of cells showed that the S. platensis biomass assimilated Cr(III) in necessary concentrations under the selected conditions retained its protein composition and useful natural properties, and, hence, could be used for medical and preventive purposes.