Effect of Coexisting Bacteria on Growth of Blue-Green Algae, Spirulina platensis

Abstract

To clarify the effect of coexisting bacteria on the growth of the blue-green algae S. platensis, coexisting bacteria were isolated from S. platensis medium and identified. Bacillus pseudofirmus and Halomonas sp. coexisted with S. platensis. The specific growth rate of S. platensis without coexisting bacteria decreased in both the cases of photoautotrophic and heterotrophic cultures. The specific growth rate of S. platensis was restored when adding coexisting bacteria. In the case of the heterotrophic culture, coexistence of Halomonas sp. is desirable to increase the maximum growth of S. platensis.