Effects of different stress factors on growth, pigment, lipid and protein amount of Chlorella vulgaris and Scenedesmus acutus

In this study, individual number, dry-weight, total chlorophyll, protein and lipid amount of Chlorella vulgaris and Scenedesmus acutus were investigated to effects in different photoperiods, illuminance, temperature and nitrogen starvations. It was observed that there was an increased in the individual numbers, protein, total chlorophyll and biomass of C. vulgaris and S. acutus in long photoperiod. Temperature was effected the individual number, biomass, total chlorophyll and protein amount of C. vulgaris and S. acutus. The effects of the changes in nitrogen amount in the culture medium on the protein and lipid amounts of C. vulgaris and S. acutus have been examined. It has been observed that nitrogen starvation does not have significant effects on the cell division of C. vulgaris and S. acutus. It has been observed that nitrogen starvation does not prevent cell development during the ten day experiment period, but that it caused a decrease in the protein amount after the eighth day. It has been observed that nitrogen amount is sufficient for cell development in the medium and that the development of C. vulgaris and S. acutus will stop after this amount decreases. It has also been determined that nitrogen deficiency causes lipid accumulation in C. vulgaris and S. acutus and that the lipid amount has increased by about 80 %. It has been concluded that nitrogen stress changes carbon flow from protein synthesis to lipid synthesis thus causing lipid accumulation in C. vulgaris and S. acutus. Key Words: Chlorella vulgaris, Scenedesmus acutus, Nitrogen Starvations, Biodiesel, Lipid, Protein, Photoperiod