Effects of light intensity and glucose concentration on the growth of Spirulina platensis

Abstract

The effects of light intensity and glucose concentration on the cellular growth of Spirulina platensis were investigated using photoautotrophic and mixotrophic batch cultures.In photoautotrophic culture, the groWth of Spirulina platensis was affected by light intensity with an optimal light intensity of approximately 4000lx. Reduction in light intensity resulted in a signficant decrease in specific growth rate. When light intensity,was below 500 lx, no growth was observed. In mixotrophic culture, the effect of light intensity on the growth was not as significant as in the photoautotrophic culture. The growth was almost unaffected at light intensities between 2000 and 4000 lx. The highest cell dry weight concentration was 2.66x10-3kg / L at the glucose concentration of 2.5x 10-3kg/L. The effects of light intensity and glucose concentration on the growth were concomitant.When tight intensity reduced from 4000 to 500 lx, the glucose concentration supporting the highest growth rate varied from 2.50x 10-3 to 5. 00x10-3kg/L.