Effect of soil extracts concentration on specific growth rate and lipid content of Chlorella vulgaris in Bolds Basal Medium

Effective nutrient medium is the key factor that significantly influences the specific growth rate and the final concentration of microalgae. The main objective of this study was to increase the microalgal growth in mass culture system under the effect of soil extract in the modified Bolds Basal medium. Chlorella vulgaris was grown asceptically for 10 days at five different concentrations of soil extract (10, 20, 30, 40, and50ml/L) at 25 degrees C cultivation temperature. After 10 days of cultivation, Chlorella vulgaris showed maximum cell concentration of 5x107/ml at 30ml/L of soil extract concentration which corresponds to the maximum specific growth rate 1.56 mu d(-1)with the doubling rate of 2.25d(-1) and lipid yield of 22.74 % of dry weight.