The 8th International Symposium on Biocontrol and Biotechnology 127 Effects of Urea and Light Intensity on the Growth of Chlorella sp.

The cultivation of Chlorella sp., isolated from natural pond using urea as a nitrogen source in glass column and fermenter was investigated. The cultivation in modified N–8 medium containing 1000 mgL-1 urea at a light intensity of 5000 lux supported good growth of Chlorella sp. E1708. The results showed that the maximum cell concentration and cell dry weight were 3.88 x 108 cells.mL-1 and 19.82 gL-1 respectively on day 8 of cultivation in a 300 mL glass column. Chlorella sp. E1708 exhibited the highest yield, showing maximum cell concentration and cell dry weight of 2.96 x 108 cells.mL-1 and 18.37 gL-1, respectively on day 5 of cultivation in the modified medium in a 5 L-fermenter at 100 rpm agitation and 3 Lmin-1 aeration. Key words: Chlorella sp., urea, light intensity, cultivation, stirred tank reactor 1