Study of growth, ammonium release and nitrate reductase activity of green algae Dunaliella salina in salinity stress, low light and CO2 conditions

Abstract

The ability of green microalgae, Dunaliella salina for existence, growth, nitrat reductase activity and ammonium release in low light, ambient CO2 and saline condition was studied for a better understanding of it is biotechnological importance. Samples were cultivated in Johnson medium whit NaCl, 7.5, 15, 30 and 50% or without NaCl(control), 30◦C±1◦C, continious white light, 1500 lux, provided by fluorescent lamps and were aerated continiously using aquarium pumps. Based on the results of the present research, the best growth obtained in NaCl 7.5% for along term period, although in short term, a very high growth rate was obtained in NaCl 50% (Saturated salinity). Ammonium release was maximum in NaCl 50% and the nitrate reductase activity was minimum in the same salinity but there was no statistically significant correlation between ammonium release and nitrate reductase activity. The ability of Dunaliella salina in releasing high amount of ammonium and growth in low and high salinity makes it an important candidate as a new biofertilizer.

Keywords

• ammonium release
• dunaliella
• green algae
• nitrate reductase
• salinity