Differences in adaptation to light and temperature extremes of Chlorella sorokiniana strains isolated from a wastewater lagoon

Presently, two Chlorella sorokiniana strains sampled during summer (CS-S) and winter (CS-W) from a maturation pond and isolated by dominance were studied on their behavior on temperature and light extremes in batch experiments. Although both strains showed no differences in their tolerance of temperatures up to 45 degrees C, the growth rates, pigment contents and fatty acid compositions in response to PAR at 700 and 1,500 mu mol m(-2) sec(-1) differed. CS-W was less affected by photoinhibition and maintained constantly high growth rates. High radiation resulted in both strains in an equivalent decrease of chlorophyll a and accessory pigments indicating that the latter did not function as a light filter. PUFAS (18:3 and 16:3) increased in CS-W at high radiation by > 60% and decreased in CS-S by 8 %. Results indicate that CS-W is highly favorable for mass cultivation particularly in outdoors, in which diurnal variations of solar radiation occur.

Automated summary

Two Chlorella sorokiniana strains sampled in summer and winter from a maturation pond and studied under extreme temperature and light conditions showed differences in growth rates and pigment contents, with the winter strain being more favorable for mass cultivation particularly in environments where diurnal variations in solar radiation occur.