Investigation on growth conditions and carotenoid acuumulation of Dunaliella viridis isolated from different salt lakes and saltwokrs in Turkey

Members of Dunaliella genus naturally occur in salt lakes and solar saltworks in Turkey. In this study, five Dunaliella viridis strains were isolated from Gelibolu salt lake (Çanakkale), Dalyan salt lake (Çanakkale), Gökçeada salt lake (Çanakkale), Çamaltı solar saltwork (İzmir) and Ayvalık solar salt work (Balıkesir). This strains were used in three different experimental groups. First experiment was conducted at laboratory conditions using different temperature (25 and 28oC), salinity (1M, 2M 3M NaCl) and light intensities (50 and 75 µmol photon m-2 s-1). Second and third experiments were performed in outdoors applying three salinity degrees (1M, 2M and 3M). It was determined in this study that changes in these factors had a significant effects on cell division, growth rate, cell volume, total chlorophyll and carotenoid accumulation.In laboratory experiments, D. viridis Gelibolu strain grew optimally at 1M NaCl, 25 oC and 75 µmol photon m-2 s-1 but maximum carotenoid accumulation was observed on Dalyan strain which was cultured at 2M NaCl, 25 oC and 50 µmol photon m-2 s-1. In the experimental groups outdoors, total chlorophyll and carotenoid contents of the cells were lower. The highest carotenoid accumulation was achieved at Çamaltı strain at 2M NaCl. In relation to the pigment content, none of the strains turned to orange or red color under the whole range of salt concentrations assayed. As a result of study, species isolated from research area was described as D. viridis and it will be constitue source for future studies.