Stimulating and inhibiting effect of Spirulina platensis on microorganisms

The blue-green microalga (cyanobacterium) S. platensis and the complex of its metabolites in the culture fluid being added into nutrient agar in doses of 0.01, 0.1 and 10 mg/ml, may produce a stimulating and inhibiting effect on microorganisms. In Spirulina biomass and in culture fluid substances which may be associated with the stimulation or inhibition of the growth of some microorganisms are supposedly contained. The manifestation of stimulating or inhibiting properties depended on the concentration of S. platensis and the complex of its metabolites, as well as on sterilization methods of nutrient media supplemented with these substances.