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The aim of the study was to investigate the influence of physical conditions such as aeration rate (1, 3, 5 L/min) as well as chemical conditions including sodium nitrite (NaNO2), urea (CH4N2O) and ammonium chloride (NH4Cl) on the biomass productivity and fucoxanthin concentration of A. capitellata. The optimum cultures were cultivated in f/2 medium using sodium nitrate (NaNO3) in 2 L bubbling bottle photobioreactors under the light intensity of 100 µE/ m2s with aeration rate of 2 L/min. All the bottles were then incubated at 22.0±2°C, under the light intensities of 300 µE/m2s with three different airflow rates of 1, 3, 5 L/min for 16 days. And then, culture medium was prepared with three different nitrogen sources to achieve higher biomass productivity. During the production of A. capitellata, the maximum specific growth rate of 0.166 day-1, which conformed to the doubling time of 4.166 day, was achieved at the light intensity of 300 µE/m2s with an aeration rate of 1 L/min when sodium nitrate was used. Chlorophyll-a and fucoxanthin contents were also at the highest level in the same light intensity. Dry biomass amount reached the maximum level of 0.66±0.17 g/L in case of NaNO2. In this study, it was defined that the airflow rate of 1 L/min, the light intensity of 300 µE/m2s and sodium nitrate (NaNO3) were the optimum values not only for the growth of A. capitellata cells but also for the production of biomass and a higher fucoxanthin concentration.

Bu çalışmada, farklı koşullarda üretimi gerçekleştirilen Amphora capitellata ve Tetraselmis chuii mikroalg türlerinin biyokütlelerindeki ve karotenoid miktarlarındaki değişimlere belirlenen parametrelerin etkisinin incelenmesi ve optimum koşulların belirlenmesi amaçlanmıştır. Her iki mikroalg türü için de koşulların değişiminin takibi için seçilen parametreler, ışık şiddeti, havalandırma hızı, azot türü ve oksidatif strestir. Tüm üretimlerin büyüme eğrileri çıkartılmış ve büyüme hızları hesaplanmıştır. Ayrıca karotenoid değişimlerinin takibi toplam karotenoid ve Amphora capitellata türü için fukoksantin, Tetraselmis chuii için loroksantin ile yapılmıştır. Hücrelerin belirlenmiş değişen koşullarda elde edilen verilerine dayanarak iki mikroalg türü için ayrı ayrı karar verilen optimum koşullardaki üretim panel fotobiyoreaktörde gerçekleştirilerek, bu şartlardaki üretimin de büyüme eğrileri çıkartılmış ve toplam karotenoid miktarları belirlenmiştir., In this study, it was aimed to examine the effects of the determined parameters on the changes in the biomass and carotenoid amounts of Amphora capitellata and Tetraselmis chuii microalgae species produced under different conditions and to determine the optimum conditions. The parameters chosen for monitoring the change of conditions for both microalgae species are light intensity, aeration rate, nitrogen type and oxidative stress. The growth curves of all productions were drawn and the growth rates were calculated. In addition, the follow-up of carotenoid changes was made with total carotenoid and fucoxanthin for Amphora capitellata species, and loroxanthin for Tetraselmis chuii. Based on the data obtained from the cells in the determined changing conditions, the production at the optimum conditions decided separately for the two microalgae species was carried out in a panel photobioreactor, the growth curves of the production under these conditions were also drawn, and the total carotenoid amounts were determined.