Growth and adaptation of the green alga Chlamydomonas reinhardtii on diesel exhaust particle extracts

SUMMARY: We have examined the growth and photosynthesis of liquid cultures of the eukaryotic green alga Chlamydomonas reinhardtii incubated with iso-octane extracts of diesel particulate exhaust. At concentrations up to 0.125% (v/v), the extracts led to a dose-dependent growth retardation. Higher concentrations caused cell death. After a prolonged lag phase, air-grown illuminated algae, stressed with sublethal concentrations of diesel exhaust extracts, adapted to the pollutants. Further addition of toxic extract up to a concentration of 2.5 (v/v) affected neither growth nor photosynthesis. Media of adapted and non-adapted cells were analysed by HPLC and GC-MS and the concentrations of the remaining toxic compounds were determined. The results showed that the amounts of certain components decreased during incubation with adapted cells.