Culture of Clorella sp. in outdoor columns 2. The role of initial cell concentration on the evolution of the culture <B>Culture of Clorella sp. in outdoor columns 2. The role of initial cell concentration on the evolution of the culture</B><P> </B><B>Divanach P.(1), Papapetrou M.(1), Kentouri M.(1,2)</B><I><P> (1) Institute of marine Biology of Crete<BR> (2) University of Crete</I><B><P> Abstract</B><P> The bloom performance of <I>Chlorella</I> Sp. in 1600 l outdoor translucid columns were tested under 4 initial cell concentrations. The best results in terms of speed of development and maximum cell density at plateau phase, were obtained when the initial cell concentration ranging between 1 x 10(6) - 2 x 10(6) cells/ml. Lower values gave lower or slower results while upper values did not induce higher activity<P> 15th Congress of the Hellenic Society of Biological Sciences 21-24 April 1993. Florina-Kastoria, 413-415. (In Greek)<P>