The Resistance of a New Strain Chlorella Sp. R-06/2, Isolated from an Extreme Habitat to Environmental Stress Factors

The resistance of a new strain – Chlorella sp. R-06/2, isolated from a geothermal well (42 oC) in Rupite, to stress caused by temperature, light intensity and concentration of mineral elements in the nutritive medium was studied. The results obtained showed that Chlorella sp. R-06/2 was not sensitive to high light intensity and had a high photosynthetic productivity preserved over a broad temperature range 26-39 oC. Furthermore, Chlorella sp. R-06/2 did not die when cultivated continuously at 44 oC and survived the stress temperature (51 oC) and light influence (2x8 kLx) up to 4 h. Chlorella sp. R-06/2 did not have special requirements concerning the concentration of nutrients and there was no lag phase, i.e. no adaptation was needed. After 20 days starvation, the normal growth of the culture was restored at intensive conditions. The high light, temperature and salt resistance of the studied strain as well as the relative stability of its chemical composition (proteins 39-53 %, carbohydrates 20-26 %, lipids 15-30 %, and pigments1,5-4 %) are of particular interest for further experimental work and the mass outdoor cultivation.