Materials and Reagents

1. Species:
   Three Chlorella species were used: C. vulgaris, isolated from soil samples of Livingston Island, the South Shetland Archipelago, Antarctic; C. vulgaris strain 8/1, isolated in 1968 from thermal springs in the region of Rupite, Bulgaria, and cultivated in our laboratory since 1975 and Chlorella kesslery a mesophile, from the Trebon collection.
   Cultivation: Chlorella species were cultivated on Tris Acetate Phosphate (TAP) medium under continuous light of 60 μmol/m²/s and a temperature of 23 °C ± 0.1 °C in a Phytotron GC 400 growth chamber. The species were cultivated at this temperature because it is well known, that eurythermal algae, could be grown at a wide range of temperatures.
   
2. TAP medium (see Recipes)
   
3. Sager–Granick medium (see Recipes)
   

Equipment

1. Phytotron GC 400 growth chamber (NUVE Ankara/Turkey 2009)
   
2. Microscope
   
3. Bürker chamber
   
4. Circulating water bath