Selection of microalgae for accumulation of lipid production under different growth conditions

Abstract

To achieve sustainable production of biofuel from microalgae, a welloptimized and sustained biomass production is prerequisite. One of the most important factors in obtaining oil from microalgae is the choice of the right algal species to be used. Seven isolates (Chlorella, Haematococcus, Ulothrix, Chlorococcum, Scenedesmus, Rivularia, Scytonema) of the 20 microalgal cultures isolated were selected based on their purity and growth rates. Under similar environmental conditions, Scenedesmus sp. and Chlorococcum sp. produced maximum calorific value (21.46 MJ/kg and 16.13MJ/kg) and lipid content (34.5±0.3% and 32.3±0.28%). Growth analysis in Scenedesmus sp. and Chlorococcum sp. was studied under various culture conditions such as nitrate concentrations, temperature and CO2 concentration. The most significant growth was recorded in Scenedesmus sp. and Chlorococcum sp., with N+/28ºC/CO2. Best biomass productivity was obtained at 28ºC under conditions of nitrogen sufficiently and CO2 supplementation (N+/28ºC/CO2). The adequate fatty acid profile was analysed by gas chromatography. The presence of oleic and linoleic fatty acid as major constituents makes Scenedesmus sp. and Chlorococcum sp. as suitable feedstock for biodiesel production.