This study was performed in order to evaluate the toxicity of SESAMULS® WO (Polyglyceryl- 6 Pentaoleate, Sesame Oil, Malic Acid) in Desmodesmus subspicatus. This freshwater green alga was chosen as a typical species of phytoplankton.

The system response was the reduction of growth in a series of algal cultures (test units) exposed to various concentrations of a test item. The response was evaluated as a function of the exposure concentration in comparison with the average growth of replicate, unexposed control cultures. For full expression of the system response to toxic effects (optimal sensitivity), the cultures were allowed unrestricted exponential growth under nutrient sufficient conditions and continuous light for a sufficient period of time to measure reduction of the specific growth rate.


Test Item

Designation in Test Facility 14121104N
Batch No. C0063


The test item was stored in a closed vessel dark and dry at room temperature.

Due to the poor solubility of the test item, the water-accommodated fraction (WAF) of the concentrations to be tested was prepared. This was done by weighing the nominal loads (1 mg/L, 10 mg/L and 100 mg/L), adding the appropriate amount of nutrient medium (demineralised water enriched with minerals but without algae) and shaking for 24 hours. The resulting solutions were filtrated through 0.45 μm filters.

Positive Control

Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9) was used as positive control in a separate reference test (GLP study).

Test System

Unicellular freshwater green alga.





SAG Strain Number


Taxonomic position

Chlorophyta – Chlorophyceae 

Origin and Culture

The culture of Desmodesmus subspicatus was obtained in February 2014 by MBM Sciencebridge GmbH (Institut für Pflanzenphysiologie of Universität Göttingen). The algae are kept as stock culture on solid agar at 7 °C. From the stock culture, a permanent culture was prepared. From an aliquot of the permanent culture, the pre-culture was prepared.


All solutions were sterilised before use.

Composition of the Solutions:

Stock solution I
NH4Cl 1500 mg
MgCl2*6H2O  1200 mg
CaCl2*2H2O  1800 mg
MgSO4*7H2O  1500 mg
KH2PO4  180 mg
H2O deionized  ad 1000 mL
Stock solution II
FeCl3*6H2O  64 mg
Na2EDTA*2H2O 100 mg
H2O deionized  ad 1000 mL
Stock solution III
H3BO3 185 mg
MnCl2*4H2O 415 mg
ZnCl2  3 mg
CoCl2*6H2O  1.5 mg
CuCl2*2H2O  0.01 mg
Na2MoO4*2H2O  7 mg
H2O deionized  ad 1000 mL
Stock solution IV
NaHCO3 50 mg
H2O deionized  ad 1000 mL
Stock solution I 10.0 mL
Stock solution II 1.0 mL
Stock solution III 1.0 mL
Stock solution IV 1.0 mL
H2O deionized   ad 1000 mL
Nutrient-medium (10-fold concentrated)
Stock solution I 100 mL
Stock solution II 10 mL
Stock solution III 10 mL
Stock solution IV 10 mL
H2O deionized   ad 1000 mL