Studies on the effect of different nitrogen source on the photoautotrophic growth of a freshwater microalga Chlorella ellipsoidea

Abstract

Nitrogen is an essential component needed for the growth and multiplica-tion of green microalgae. An experiment was conducted to study the effect of different sources of nitrogen on the phototrophic growth of the green microalga Chlorella ellipsoidea. Sodium nitrate, Sodium nitrite, urea, ammo-nium sulphate, ammonium nitrate and ammonium nitrite were added to BG11 medium as the sole source of nitrogen and the cultures were main-tained under in vitro condition. Highest absorbance and cell density was ob-served in the medium containing sodium nitrate followed by sodium nitrite while the medium with urea sustained poor growth of the microalgae. Thus BG11 medium containing sodium nitrate added at a concentration of 1.5g/L was found to be suitable for the cultivation of C. ellipsoidea.