Molecular characterization, culture and the effect of nitrogen and silicium limitations on lipid, protein, carbohydrate and pigment amount of some diatom species isolated from Yumurtalık Bay (Northeast Mediterranean)

In this thesis, phytoplankton sampling was carried out from Yumurtalık Bay in the Iskenderun Bay in the Northeast Mediterranean, diatom species were isolated and cultured. Detailed taxonomic positions of the isolated diatom species were determined by molecular phylogeny methods and 14 diatom species were isolated and purified. In cultured isolates (Chaetoceros calcitrans, Chaetoceros coloradensis,Chaetoceros gracilis, Chaetoceros muelleri, Entomonies paludosa, Navicula erifuga, Navicula perminuta, Navicula salinicola, Nitzschia inconspicua, Nitzschia closterium f. minutissima, Nitzschia laevis, Skeletenoma costatum, Thallassiosira pseudonana, Thallassiosira weissflogii) biochemical contents were investigated under nitrogen and silicium limitation. Nitrogen and silicium limitations decreased the optical density, dry matter, chlorophyll a, total carotene and protein content, but increased lipid, lipid productivity, fucoxanthin and carbohydrate content. The highest amount of lipids obtained was determined as 44.87±0.37% in T. weissflogii. The lowest lipid content was found to be 13.92±0.36% in E. paludosa in the control group. In Navicula salincola, the highest amount of biomass and protein were determined as 1.045 gL-1 and 32.35±0.9% in the control group, respectively, while the highest amount of 50% N (-) fucoxanthin was determined as 9.85±0.3 mg/g-1. The highest carbohydrate content was determined as 50% N (-) 31.23±0.7% in S. costatum.