HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Altenburger, R. Articles by Riedl, J. Search for Related Content PubMed PubMed Citation Articles by Altenburger, R. Articles by Riedl, J. Agricola Articles by Altenburger, R. Articles by Riedl, J. Related Collections Ecological Risk Assessment Cell Biology & Molecular Genetics Crop Models

Bioassays with Unicellular Algae: Deviations from Exponential Growth and Its Implications for Toxicity Test Results

UFZ- Helmholtz Centre for Environmental Research, Dep. Bioanalytical Ecotoxicology, Permoserstr.15, 04318 Leipzig, Germany

View larger version (5K): [in this window] [in a new window]   Fig. 1. Growth of liquid cultures of Desmodesmus subspicatus over 72 h, as detected using the in vivo red chlorophyll autofluorecence signal of suspensions after blue light excitation. The line represents an exponential regression fit for the 8 independent values each derived as a mean value from a 24 well plate.

View larger version (8K): [in this window] [in a new window]   Fig. 2. Cell population growth of Desmodesmus subspicatus between 24 and 50 h of the 72 h growth experiment at a time resolution of 2 h. Figure 2a displays the values for in vivo chlorophyll autofluorescence and the fit of the growth model provided in Eq. 1. The inset shows the values within the 72 h full experiment. Figure 2b depicts the values for cell counts for the same experiment.

View larger version (63K): [in this window] [in a new window]   Fig. 3. Cell size distributions of Desmodesmus subspicatus suspension samples between 24 and 50 h of the 72 h growth experiment at a time resolution of 2 h. The modal value was used to uniformly scale the distributions. The inset shows the derived mean cell volumes for each distribution at a given time point plus the fit of the growth model provided in Eq. 1.

View larger version (15K): [in this window] [in a new window]   Fig. 4. Contour plot of an algal sample at 42 h of a 72 h growth experiment with Desmodesmus subspicatus. Plotted are the 2000 particle specific signals for sideward light scatter against the red autofluorescence signal emitted after blue light excitation. The scale is provided in relative units.