Investigation of the Malic Acid Concentration on Extremophilic Red Microalga Galdieria Sulphuraria

Abstract

Malic acid is a dicarboxylic acid which is made by living organisms and the salts of malic acid are known as malates. Malates are used in pruvate/malate cycle that merges carbohydrate, fat and protein metabolism. Based on this cycle, the prediction was that malic acid could change carbohydrates ratio in G.sulphuraria. In this study, the effects of malic acid concentrations were investigated on growth (maximum specific growth rate and doubling time) of extremophilic, red alga Galdieria sulphuraria (SAG 108.79). By increasing malic acid concentration, specific growth rate and biomass concentration were also increased, however the highest concentration of protein (153.81±0.673 mg/L) was obtained in 5 mM. The total amount of carbohydrates was increased about 8.35%. Keywords