INFLUENCE OF NICKEL ON THE GREEN-ALGA HAEMATOCOCCUS-LACUSTRIS ROSTAFINSKI IN PHASES OF ITS LIFE-CYCLE

The influence of nickel (NiSO4 6H(2)O; 1 and 100 mu M) on the phases of germination of the resting cells (aplanospores), cell division in the flagellate stage, and during aging (formation of aplanospores) in Haematococcus lacustris was investigated. Nickel at the 1 mu M-concentration (commonly found in aquatic biotopes) had no effects on the parameters tested. However, 100 mu M Ni reduced the germination rate and the protein and chlorophyll contents; it caused slight inhibition of the phototaxis in flagellates, but was without effects on the carotenoid and carbohydrate contents and on the primary photochemistry during the germination of aplanospores. In the other phases (cell division and formation of aplanospores) the toxic effects were particularly pronounced: 100 mu M Ni strongly decreased the growth rate, pigment content, photosynthesis, and the number of motile cells; it completely inhibited the formation of aplanospores, while the velocity of movement in flagellates and the protein and carbohydrate contents were not or only slightly influenced.