Rapid ecotoxicological bioassay using delayed fluorescence in the green alga Pseudokirchneriella subcapitata

A rapid and simple ecotoxicological bioassay allows quick estimation of the effects of Simazine (CAT) or 3,5-dichlorophenol (3,5-DCP) on the growth of the green alga Pseudokirchneriella subcapitata (formerly Selenastrum capricornutum). The effects of a 15-min exposure to CAT or 3,5-DCP on delayed fluorescence (DF) in P. subcapitata were compared to the results of standard growth inhibition tests involving 72 h of exposure to these chemicals at the same concentrations. Integrated DF intensity in the time period from 0.6 to 50 s was found to correlate with algal growth inhibition as measured by the standard tests. In addition, the behaviour of DF in this time period exhibited characteristic kinetics indicative of the chemical being tested.