Asfouri N, Djalt S, Maroc F, Zelal A, Lamara S A C, Bab Hamed M B and Abi-Ayad S M E A
University of Oran, Algeria
Posters & Accepted Abstracts: J Fundam Renewable Energy Appl
Microalgae based biofuels are getting attention due to energy crisis and environmental protection. There is potential to increase yields by manipulating environmental factors, which cause stress for microalgae and induce maximum accumulation of lipids. Sources of stress include manipulating environmental conditions such as salinity, pH, temperature, and nutrients. Among 30 microalgae, Nannochloropsis gaditana was identified to have the highest biomass and lipid productivity. These are marine microalgae that are tolerant to a large range of environmental conditions. In the present study, Nannochloropsis gaditana was cultivated in F2 guillard medium at batch mode over 12 days. Here, we observe how various nitrogen treatments and temperatures can impact the growth and lipid accumulation on this species. We used five different nitrogen treatments; ammonium chloride (NH4Cl), ammonium hydroxide (NH4OH), sodium nitrate (NaNO3), urea (CH4N2O), a mixture of all these sources and three different temperatures (20├?┬░C, 25├?┬░C, 30├?┬░C). The highest biomass growth was found (0.307d-1) in ammonium chloride treatment. However, the results showed that under 30├?┬░C Nannochloropsis gaditana were found to grow favorably with a maximum growth rate 0.197d-1. The lipid content was examined using Bligh and Dyer method and found better in CH4N2O nitrogen source (47.67%). Among all the temperatures, the maximum lipid content (35.79%) was found in the case of 30├?┬░C. Our results suggest that tradeoffs between growth and lipid yields as well as culture success can ultimately decide what nitrogen sources to use. We advocate an approach that provides multiple sources of microalgae available nitrogen which may alter assimilation rates and ultimately microalgae├ó┬?┬?s physiological responses.