Effects of Culture Conditions on Growth and Biochemical Profile of Chlorella Vulgaris

The effects of culture conditions at different temperature and light regimes on growth and the contents of chlorophyll-a, chlorophyll-b, total carotenoids, total protein and total free amino acids of Chlorella vulgaris were determined. The growth of C. vulgaris in terms of optical density (0.42 at 670 nm), cell count (440 x 104 cells/ml) and dry weight (30.2 mg/50 ml), and the amount of chlorophyll-a (2.16%), chlorophyll-b (0.59%) and total protein, was found higher at the temperature 25-30C and natural day light receiving through the north facing window of the growth room. Although, the amount of total carotenoids (0.440%) and free amino acids (834 g/gm fresh weight) were found maximum in continuous light at 30-35C, not much differences in the amount of carotenoids (0.385%) and free amino acids (822 g/gm fresh weight) were found at 25-30C and natural day light. The natural day light at 25-30C was also proved proficient, as distinct banding pattern with unique polypeptides such as 15KDa, 47KDa and 50KDa, on the other hand, 23KDa, 26KDa and 36KDa appeared in all samples, these bands were not affected by light and temperature. Our results indicate that among all five culture conditions tested, the cultures kept at north facing window receiving natural day light at temperature 25-30C, show best growth and higher contents of biochemicals that will be beneficial to use Chlorella for high nutritive purpose.