Production of Biomass and γ-Linolenic Acid Production by Spirulina platensis Under Different Temperature and Nitrogen Regimes

Abstract

Spirulina is of the worldwide cultivated and consumed microalgae. It is generally used directly or as an additive in the food industry due to its high protein content. Besides the high protein content, Spirulina biomass contains important fatty acids, (e.g. GLA), vitamins, minerals and other bioactive compounds. These important compounds are affected by the parameters of biomass cultivation. In the presented study, the limitation of nitrogen (25%, 50%, 75% and 100% N concentration) and temperature fluctuations (25°C and 30°C) on Spirulina platensis biomass yield, lipids and fatty acid profile were investigated with the comparison of Spirulina medium and Zarrouk medium. In the present investigation, the production of Spirulina platensis was optimized in terms of biomass and metabolites. With the increase in temperature, while the amount of biomass increased in general, dry weight decreased. The highest level of lipid accumulation was determined as 12.31 ± 1.72 % for the sample 25°C, Spirulina medium and 50% N concentration. Protein, lipid, total phenolic substance, and total carotenoid amounts were found at the highest level with the temperature increase to 30°C in all samples except the sample with the highest oil content. Consequently, the highest PUFA values were found in 30°C, Zarrouk medium and 75% N concentration as 42.610%, whereas GLA was 25°C, Zarrouk medium and 100% N concentration as 24.735%. On the other hand, GLA values were determined significantly high both during growth at 25°C and 30°C in Zarrouk medium.