In order to find out optimum culture condition for algal growth, the effect of light irradiance and temperature on growth rate, biomass composition and pigment production of Spirulina platensis were studied in axenic batch cultures. Growth kinetics of cultures showed a wide range of temperature tolerance from 20 degrees C to 40 degrees C. Maximum growth rate, cell production with maximum accumulation of chlorophyll and phycobilliproteins were found at temperature 35 degrees C and 2,000 lux light intensity. But with further increase in temperature and light intensity, reduction in growth rate was observed. Carotenoid content was found maximum at 3,500 lux. Improvement in the carotenoid content with increase in light intensity is an adaptive mechanism of cyanobacterium S. platensis for photoprotection, could be a good basis for the exploitation of microalgae as a source of biopigments.
