BAZI YEŞİL MİKROALGLERİN KAROTENOİD PROFİLLERİN BELİRLENMESİ
Project no. 561 · Status: Kapanmış · 2017
Summary
In this study three different stress parameters (mixing speed (100-250 rpm), light intensity (100-400 µE/m2s) and nitrogen limitation (0-17.65 mM)) were applied on the green microalgae and these parameters were optimized to get maximum total carotenoid amount. Nitrogen limitation are known to induce important physiological changes especially in carotenoid and lipid metabolism of microalgae. Optimum stress parameters for four microalgae species (Chlorella vulgaris, Ankistrodesmus convolutus, Tetraselmis striata, Dunaliella salina) were determined by the statistical analysis method. The regression coefficient (R2>0.90) is within acceptable limits for all optimization models. Total carotenoid amounts of species produced in optimum conditions; Chlorella vulgaris 23.78 mg/g biomass, Ankistrodesmus convolutus 24.13 mg/g biomass, Tetraselmis striata 8.59 mg/g biomass and Dunaliella salina 5.51 mg/g biomass. Since the highest total carotenoid amount for A. convolutes was found at 250 rpm mixing speed, light intensity of 200.94 µE/m2s and nitrogen concentration of 11.06 mM, this microalga was produced in a panel photobioreactor under optimum conditions. At the end of the production 4.55 g dry biomass was obtained. It was calculated that 20.86 mg/g biomass chlorophyll a, 54.86 mg/g biomass chlorophyll b and 35.72 mg/g biomass total carotenoid were produced in the biomass. The most efficient cell disruption technique, to facilitate the extraction of dry biomass harvested from the reactor, is steel beads. Ultrasonic extraction and microwave extraction were performed after the most efficient cell disruption technique was selected. Extracts were analyzed by HPLC-DAD. The total amount of carotenoid in the sample obtained by ultrasonic extraction was 0.98 mg/g biomass. With this study, the conditions of carotenoid production of green microalgae isolated from biodiversity of our country, have been determined and profiled. In addition, the study has been prepared with the content and authenticity that could lead to further academic work.