Abstract

M. Golam Mortuza , Toshiyuki Takahashi , Tatsuya Ueki , Toshikazu Kosaka , Hitoshi Michibata and Hiroshi Hosoya

The effects of hexavalent chromium on the cell growth of paramecium, Paramecium bursaria were investigated. Five strains (KBW-2, KNN-2, KNN-3, IM-6 and F1-6a) of P. bursaria (both symbiotic and algae free) were incubated in lettuce media supplemented with different concentrations of potassium dichromate under LD (12 h light: 12 h dark) conditions. To compare the bioaccumulation of chromium in symbiotic and algae free strains of P. bursaria, the concentration of chromium in cell pellet has been analyzed and calculated. The average amount of chromium accumulated in paramecium was ranged from 1.53 to 42.12 pg Cr/cell at concentration-dependent manner after 7-day of incubation. The results show that the symbiotic and algae free strains of P. bursaria can accumulate chromium and chromium accumulation ability of symbiotic strains is higher than that of algae free strains. This suggests that interactive effect of paramecium and algal cell was generally found to be synergistic in chromium accumulation for symbiotic paramecia.