OPTIMIZATION STUDIES FOR MICROALGAL GROWTH AND CAROTENOID PRODUCTION (BEFORE STRESS)

Abstract

The demand for carotenoids in the global market is rising due to the high rate of degenerative diseases which have their origin from deleterious free radicals. Carotenoids are antioxidant molecules identified as the potential inhibitors of free radicles. Particularly, Microalgae carotenoids have drawn great attention, ‘due to their high photosynthetic efficiency, lack of land requirement, and ease of scale-up’. Presently, an attempt was made to optimize the primary growth of three microalgae (i.e., Chlorella vulgaris, Microcystis aeruginosa and Scenedesmus obliquus) prior to second fermentation for the production of carotenoids. Response surface methodology (RSM) was used to optimize experimental runs in an orbital shaker (Winpact SI-200, USA) in a controlled setting of pH and temperature. Growth of microalgae was measured as optical density (OD) as well as the total carotenoids (before stress) at the stationary growth stage. Optimum growth of Microalgae was achieved at a range of 250C -300C and pH 8-9 in all the Microalgae. High carotenoids (before stress) was 4.411mg/ml in Scenedesmus obliquus among others; however, this cannot be translated as the highest as carotenoids are optimized during stress.