Effects of nitrate and ph sphate on the growth and total lipid contents of Chlorella oocystoides and Chlorella minutissima ( Chlorophyceae)

Abstract

The effects of different concentrations (0.1, 0.5, 1.5 and 4.5 ppm) of nitrate (NO3-) as NaNO3 and phosphate ( PO4---) asK2HPO4 on growth parameters (dry weight, optical density, total pigments), total lipid, total carbohydrate and total protein contents of Chlorella oocystoides and Chlorella minutissima cultured were followed for 7 days.The growth parameters (dry weight, optical density and total pigments), total carbohydrate and total protein contents ofChlorella oocystoides and Chlorella minutissima were significantly increased up to the concentration 1.5 ppm of NO3- andPO4--- Under relatively higher concentration 4.5 ppm of NO3- and PO4--- all these parameters were significantly decreased. On the contrary, the total lipid contents were significantly increased up to the 0.1 ppm of NO3- and PO4--- However, under relatively higher concentration 4.5 ppm of NO3- and PO4---, the total lipid contents were significantly decreased