trans-menthone

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge nitrification inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data is from Peer reviewed journal

Justification for type of information:

Data is from Peer reviewed journal

Qualifier:

according to guideline

Guideline:

other: As mention below

Version / remarks:

No data

Principles of method if other than guideline:

Toxicity of menthone on the microorganisms Pseudomonas citronellolis DSM 50332 was studied for 21 days.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (IUPAC name): (2R,5S)-5-methyl-2-(propan-2-yl)cyclohexan-1-one- Common name: Menthone - Molecular formula: C10H18O- Molecular weight: 154.2512 g/mol- Smiles notation: C1([C@@H](CC[C@@H](C1)C)C(C)C)=O- InChl: 1S/C10H18O/c1-7(2)9-5-4-8(3)6-10(9)11/h7-9H,4-6H2,1-3H3- Substance type: Organic- Physical state: Liquid

Analytical monitoring:

yes

Details on sampling:

No data available

Vehicle:

yes

Test organisms (species):

other: Pseudomonas citronellolis DSM 50332

Details on inoculum:

- Laboratory culture: Pseudomonas citronellolis DSM 50332 was obtained from the Deutsche Sammlung von Mikroorganismen, Braunschweig, Germany. - Name and location of sewage treatment plant where inoculum was collected: Deutsche Sammlung von Mikroorganismen, Braunschweig, Germany.- Method of cultivation: no data - Preparation of inoculum for exposure: Pure cultures were isolated anaerobically on agar bottle plates in which the substrate was provided by diffusion from a reservoir through the gas phase to the agar surface (10, 19). During all manipulations, the bottles containing the agar were flushed with N2-CO2 (90:10, vol/vol) by using a Hungate syringe. A 20-ml portion of liquid anoxic medium containing 1.5% washed agar was prepared with chelated trace elements instead of non-chelated trace elements (20) and with 50 mM carbonate instead of the phosphate-carbonate buffer above, dispensed into a 100-ml bottle, and solidified quickly by placing the bottle on a plastic bag filled with ice. After inoculation, the agar bottles were inverted, and 75 ml of monoterpene in 3 ml of HMN was added to each bottle. During incubation, the bottles were kept horizontal with the agar aloft. Direct contact between the organic phase and the agar was avoided- Pretreatment: no data- Initial biomass concentration: no data

Test type:

other: Agar diffusion method.

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Remarks on exposure duration:

Test conducted for 10 days to 21 days.

Post exposure observation period:

No data available

Hardness:

No data

Test temperature:

mesophilic temperature

pH:

7

Dissolved oxygen:

No data

Salinity:

No data

Conductivity:

No data

Nominal and measured concentrations:

Nominal

Details on test conditions:

- Test vessel: Glass bottels- Material, size, headspace, fill volume: 0.5 liter of glass bottles that contained 400 ml of medium, 4 ml of HMN, and 200 ml of liquid substrate- Biomass loading rate: 0.5-liter bottles that contained 400 ml of medium, 4 ml of HMN, and 200 ml of liquid substrate or 200 mg of solid substrate under an N2-CO2 (90:10, vol/vol). A 100-ml portion of the water-mud mixture from the ditch was inoculated into each bottle together with 350 ml of medium, 8 ml of HMN, and 400 ml or 400 mg of substrate. - Photoperiod: performed in dark

Reference substance (positive control):

no

Remarks:

other: Pasteurized samples and inoculated preparations without nitrate or monoterpene were used as controls.

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

308 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of anaerobic gas production

Remarks on result:

other: No inhibition was observed

Details on results:

No data available

Results with reference substance (positive control):

No data available

Reported statistics and error estimates:

No data available

Validity criteria fulfilled:

not specified

Conclusions:

On the basis of no growth inhibition of microorganisms Pseudomonas citronellolis due to the menthone for 10 days to 3 weeks, the NOEC was 308 mg/l (2mM)

Executive summary:

Toxicity of menthone on the growth of microorganisms Pseudomonas citronellol is DSM 50332 for 21 days. Analytical grade samples were used for the test. Test performed in 0.5 liter of agar bottle plates by using the pure culture of microorganism providing proper temperature and PH. Culture were inoculated in dark having the mesophilic temperature. Growth inhibition of Pseudomonas citronellolis was observed at 2m M of concentration of menthone for minimum 10 days to 3 weeks. Analytical grade samples were used for the test. Thus after the exposure with chemical no inhibition was observed. On the basis of no growth inhibition of microorganisms Pseudomonas citronellolis due to the menthone for 10 days to 3 weeks, the NOEC was 308 mg/l (2mM).

Description of key information

Toxicity of menthone on the growth of microorganismsPseudomonas citronellol isDSM 50332 for 21 days. Analytical grade samples were used for the test. Test performed in 0.5 liter of agar bottle plates by using the pure culture of microorganism providing proper temperature and PH. Culture were inoculated in dark having the mesophilic temperature. Growth inhibition of Pseudomonas citronellolis was observed at 2m M of concentration of menthone for minimum 10 days to 3 weeks. Analytical grade samples were used for the test. Thus after the exposure with chemical no inhibition was observed. On the basis of no growth inhibition of microorganisms Pseudomonas citronellolis due to the menthone for 10 days to 3 weeks, the NOEC was 308 mg/l (2mM).

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

308 mg/L

Additional information

Toxicity of menthone on the growth of microorganisms Pseudomonas citronellol is DSM 50332 for 21 days. Analytical grade samples were used for the test. Test performed in 0.5 liter of agar bottle plates by using the pure culture of microorganism providing proper temperature and PH. Culture were inoculated in dark having the mesophilic temperature. Growth inhibition of Pseudomonas citronelloliswas observed at 2m M of concentration of menthone for minimum 10 days to 3 weeks. Analytical grade samples were used for the test. Thus after the exposure with chemical no inhibition was observed. On the basis of no growth inhibition of microorganisms Pseudomonas citronellolis due to the menthone for 10 days to 3 weeks, the NOEC was 308 mg/l (2mM).