EFFECT OF CULTURE TEMPERATURE SHIFT ON THE CELLULAR SUGAR ACCUMULATION OF CHLORELLA-VULGARIS SO-26

We investigated the effect of culture temperature on the maximum speci fic growth rate and cellular sugar accumulation, and the effect of a t emperature shift on the sugar accumulation of cells of an Antarctic gr een alga, Chlorella vulgaris SO-26, in a batch culture system. Decreas es in temperature appeared to correlate with decreases in the maximum specific growth rate; on the other hand, the cellular sugar content sh owed a reverse tendency against temperature. We attempted to use this tendency to improve sugar productivity in Chlorella. First, we culture d Chlorella at 20 degrees C during the logarithmic growth phase to obt ain a high specific growth rate. The culture temperature was then shif ted from 20 degrees C to 14 degrees C during the stationary growth pha se to increase the cellular sugar content. As a result, we obtained a 25% increase in sugar production over that obtained by culture at 20 d egrees C throughout the culture.