N,N-diethyl-2-propynylamine

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms, other

Remarks:

Pseudomonas growth inhibition test

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (as cited in study report): Golpanol DEP

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Pseudomonas putida

Details on inoculum:

CULTURING CONDITIONS
- Strain: DSM 50026
- Temperature: 23 - 25 °C
- Shaking: yes; 150 rpm
- Vessel: 300 mL Erlenmeyer, containing 100 mL culture medium
- Growth period: 6 - 8 h
- Pretreatment: No pretreatment

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

16 h

Test temperature:

20 °C

Nominal and measured concentrations:

- Nominal concentrations: 0 (control), 39.531, 78.125, 156.25, 312.5, 625, 1250, 2500, 5000, 7500 and 10000 mg/L (based on a range-finding study).

Details on test conditions:

TEST APPROACH
All test vessels contain 0.5 mL nutrient solution concentrate 1, 0.5 mL nutrient solution concentrate 2, 1 mL bacterial suspension in NaCl solution set to 10 TE/F and 8 mL test substance solution (concentration f = 1.25).
- No. of vessels per concentration: 4
- No. of vessels per control: 4

TEST PARAMETERS MEASURED: optical density
Bacterial growth (inhibition) was determined optically by means of spectrophotometry at a wavelength of 436 nm and compared to a blank control.

RANGE-FINDING STUDY
- Nominal concentrations: 0 (control), 15.625, 31.25, 62.5, 125, 250, 500, 100 and 2000 mg/L.
- Results used to determine the conditions for the definitive study: Up to 250 mg/L, no inhibition was observed. From 500 to 2000 mg/L, inhibition increased in a dose-dependent manner. The EC50 and EC10 values were determined to be 1149.5 and 4664 mg/L, respectively.

Reference substance (positive control):

no

Key result

Duration:

16 h

Dose descriptor:

EC50

Effect conc.:

1 628 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Key result

Duration:

16 h

Dose descriptor:

EC10

Effect conc.:

769 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Details on results:

Up to and including the dose group of 625 mg/L, no inhibition was observed. From 1250 mg/L to 10000 mg/L, the measured density decreased in a dose-dependent manner from 65.81% to 0.24 % relative to the control, respectively. An overview of the results is provided in 'Any other information on results incl. tables'.

Table: Optical density of the P. putida cell suspension compared to control measured at 436 nm.

Concentration in mg/L	Inoculated	Uninoculated	Difference	% of control
Control	0.418	---	---	---
39.531	0.426	0.002	0.424	101.62
78.125	0.433	0.002	0.431	103.11
156.25	0.438	0.001	0.437	104.73
312.5	0.446	0.001	0.445	106.59
625	0.407	0.001	0.406	97.25
1250	0.276	0.001	0.275	65.81
2500	0.059	0.002	0.057	13.53
5000	0.002	0.000	0.002	0.48
7500	0.001	0.000	0.001	0.24
10000	0.001	0.000	0.001	0.24

ADDITIONAL EFFECT VALUES

- 16-h EC90: 3176.6 mg/L

Validity criteria fulfilled:

not specified

Description of key information

The 16-h EC50 and EC10 values are 1628 and 769 mg/L as observed in a bacterial growth inhibition study (Pseudomonas putida).

Additional information

The toxicity of the substance to microorganisms was investigated in a bacterial growth inhibition study according to guideline DIN 38412, part 8 (BASF, 1987). In this study, cultures of bacteria (Pseudomonas putida) were exposed to nominal test substance concentrations of 0 (control), 39.531, 78.125, 156.25, 312.5, 625, 1250, 2500, 5000, 7500 and 10000 mg/L (based on a range-finding study) for 16 hours. Test concentrations were not analytically verified. Bacterial growth (inhibition) was determined optically by means of spectrophotometry at a wavelength of 436 nm and compared to a blank control. Up to and including the dose group of 625 mg/L no inhibition was observed. At a test concentration of 1250 mg/L, 34.19% cell growth inhibition was observed. At higher test concentrations the growth inhibition came close to 100%. Based on these findings, the 16-h EC50 and 16-h EC10 values were determined at 1628 mg/L and 769 mg/L, respectively.