Effect of reducing the light intensity on the growth and production of chlorophyll by Spirulina platensis

The influence of light intensity reduction on Spirulina platensis cultivation was investigated, using urea and KNO3 as nitrogen sources. The reduction of light intensity from 5 to 2 klux was studied both on the 9th and the 13th day of cultivation. Increases of up to 29% in the total chlorophyll production were observed for the cultivations with light intensity reduction, in comparison with the cultivations carried out at fixed light intensities.