N-(N6-trifluoroacetyl-L-lysyl)-L-proline

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1996-03-12 to 1997-02-17

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)

Version / remarks:

1991

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method:
The test substance was applied as a stock solution of 10 g test substance. For this purpose 10 g of test substance was dissolved in 800 mL demineralized water and filled up to 900 litre with 12.5 mL of solution II and Ill and 25 mL with solution IV.
Solution I
20,0 g NaNO3
4,8 g K2HPO4
1,0 g Yeast extract
2,4 g KH2PO4
were dissolved in 1 L of deionized water .
Solution II
20,0 g NaNO3
4,8 g K2HPO,
2,4 g KH2PO4
were dissolved in 1 L of deionized water .
Solution III
88,0 g Glucose-Monohydrate
were dissolved in 1 L of deionized water.
Solution IV
4,0 g MgSO4 x 7 H2O
0,01 g Iron citrate
were dissolved in 1 L of deionized water.
To 800 mL of 10 g dissolved test substance, 12.5 mL of solution II and solution III respectively and 25 mL of solution IV were added. The test solution was divided into 5 equal amounts of 90 mL, four of which were filled into Erlenmeyer flasks (except in the case of the extract with the highest content, where all 5 portions were used). Parallel to the mixtures with test substance, 30 mL of solution II and solution III respectively and 60 mL of solution IV were added to 960 mL of demineralized water and this control solution was divided into 12 portions of 90 mL each. The solutions II to IV were prepared according to DIN 38412, Part 8. The test solutions were filled up to 100 mL with 10 mL of an inoculum ofPseudomonas putida MIGULA in the exponential growth phase. During incubation and to avoid contamination, the test solutions were closed with cotton wool plugs, that were pervious to air. A reagent zero value was determined for each concentration by replacing the inoculum with the test medium.

Test organisms (species):

Pseudomonas putida

Details on inoculum:

- Laboratory culture: The test organism, Pseudomonas putida MIGULA strain Berlin, laboratory stock culture according to Institut Fresenius SOP Ö 022, served as test system. Supplier: DSM (Deutsche Stammsammlung von Mikroorganismen und Zellkulturen GmbH)

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

16 h

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- Type (delete if not applicable): closed
- No. of vessels per concentration (replicates): 5
- No. of vessels per control (replicates): 6
- No. of vessels per abiotic control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: According to DIN 38412, part 8

OTHER TEST CONDITIONS
- Adjustment of pH: no

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : After completion of the incubation the extinction of the control at 436 nm and therefore the bacterial density was determined, in order to detect the minimum bacterial proliferation in the control solution. The pH-value was determined in one control solution and in one test solution with the highest concentration. In order to determine the inhibiting effect of the test substance on the test system the test solutions were measured by means of a photometer to be 436 nm against the control without any test substance.

TEST CONCENTRATIONS
10 g/L as recommended by the guideline

Reference substance (positive control):

no

Key result

Duration:

16 h

Dose descriptor:

NOEC

Effect conc.:

10 g/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Validity criteria fulfilled:

yes

Conclusions:

In the present test conducted according to DIN 38412 part 8, Pseudomonas putida was subjected to different concentrations ofthe test substance. After 16 ± 1 hours incubation time the bacterial density was determined in the test solutions and compared with a control solution without test substance. Under the conditions used in this study no chronic toxic effect at the highest test concentration 10 g/L could be detected in the test system, Pseudomonas putida.

Description of key information

In a study conducted according to DIN 38412 part 8, Pseudomonas putida was subjected to different concentrations of ε-trifluoracetyl-L-lysyl-L-proline (TFA-Lys-Pro). After 16 ± 1 hours incubation time no chronic toxic effect at the highest test concentration of 10 g/L could be detected.

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

10 g/L