The effect of temperature,Ca2+, Mg2+ and Ni2+ ions on the swimming speed of C. reinhardii determined by quasi-elastic light scattering

Quasi-elastic light scattering was used to measure the motility of Chlamydomonas reinhardii (wild type) under varying environments of temperature and ionic concentration (Ca²⁺, Mg²⁺, Ni²⁺). The results obtained agree with the results obtained by other techniques where comparison was available. The advantage of this method is that it provides these results in minutes. In many cases this rapid analysis can be used to follow the change in motility which arises after a chemical or physical perturbation. The speed of the cell, and the average flagellar force, was found to increase as the temperature was varied between 6 and 40 °C. The cell seemed to be irreversibly damaged at temperatures above 40 °C. The speed of the cell was found to be very dependent on [Ca²⁺]. The cell's speed slowed very significantly as the concentration of Ca²⁺ was reduced and was also found to be relatively independent of the Mg²⁺ concentration between 10^?3 and 10^?10 M. The addition of Ni²⁺ to the cells' environment resulted in the cell speed increasing significantly over the short term, with the long-term effect being a net decrease in the cells' speed.