(2S)-5-amino-2-[(aminoacetyl)amino]-5-oxopentanoic acid

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-09-28 to 2009-10-01

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

23 March, 2006

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

24 August, 2009

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 6.25, 25 and 100 mg/L after 0, 24, 48 and 72 h

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: a stock solution with a concentration of 1 g a.i./L was prepared. The required amount of test material was added to the test medium and stirred for 15 minutes. The test concentrations wer prepared separately by dilution of the stock solution.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Strain: 86.81
- Source: Obtained from "Sammlung von Algenkulturen", Göttingen (SAG), (Collection of Algae Cultures, Institute for Plant physiology), University of Göttingen, Germany
- Method of cultivation: cultured at 25 ± 1 °C and 8000 ± 1000 Lux

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

24.9 - 25.1 °C

pH:

Control: 8.13 (start) - 9.30 (end)
Treatment: 7.42 - 7.83 (start), 8.61 - 10.26 (end)

Nominal and measured concentrations:

Nominal test substance concentrations: control, 6.25, 12.5, 25, 50, 100 mg a.i./L
Recovery rate of DOC: 88 - 99%

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlendmeyer flasks (300 mL) with cotton-wool plugs
- Material, fill volume, headspace: glass, 150 mL, 150 mL
- Initial cells density: 5000 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: prepared according to OECD 201
- Intervals of water quality measurement: pH at start end end of exposure period, temperature daily

OTHER TEST CONDITIONS
- Light intensity and quality: 8000 Lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable)
- Determination of cell concentrations: photometrically (spectrophotometer at a wavelength of 578 nm) after 0, 24, 48 and 72 h

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Range finding study: yes

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Results with reference substance (positive control):

- Results with reference substance valid? Yes (Test conducted 2009-04-17 to 2009-04-23)
- EC50: ErC50 (72 h): 0.9 mg/L

Reported statistics and error estimates:

Statistical evaluation was performed using ToxRat® professional.

Validity criteria fulfilled:

yes

Conclusions:

The results of this study show that the test substance Glycyl-L-glutamine monohydrate induced no inhibition of algal growth after 72 h of exposure. For the parameter yield the EyC50 value was >100 mg a.i./L and the LOEC and NOEC values were >100 mg a.i./L and ≥100 mg a.i./L, respectively, after 72 h of exposure, based on nominal concentrations. For the parameter growth rate the ErC50 value was >100 mg a.i./L and the LOEC and NOEC values were >100 mg a.i./L and ≥100 mg a.i./L, respectively, after 72 h of exposure, based on nominal concentrations.

Description of key information

ErC10/50 (72 h) > 100 mg/L (nominal, OECD 201)

Key value for chemical safety assessment

EC10 or NOEC for freshwater algae:

100 mg/L

Additional information

The toxicity of the substance to aquatic algae was investigated in a study following OECD 201 (GLP). The study was conducted using Desmodesmus subspicatus as test organism. The algae were exposed to nominal test substance concentrations of 6.25, 12.5, 25, 50, 100 mg a.i./L including a control for 72 hours. The test substance concentration was analytically verified by DOC analysis and the recovery rate was 88 - 99% of nominal. An inhibition of algal growth was not observed. An ErC10/50 (72 h) > 100 mg/L was determined based on growth rate of algal cells.