Disodium 2-(2,4,5,7-tetrabromo-6-oxido-3-oxoxanthen-9-yl)benzoate

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms

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: refer below principle

Principles of method if other than guideline:

Toxicity to micro-organisms study was conducted on Staphylococcus aureus of enterotoxigenic strain ATCC 13565.

GLP compliance:

not specified

Analytical monitoring:

not specified

Details on sampling:

- Concentrations: 100 µg/ml (0.1 mg/ml)
- Sampling method: For the preparation of dye solution, a test portion (approximately 10 mg) was placed in a 10-ml volumetric flask, which was wrapped in aluminum foil, and dissolved by adding aqueous sodium hydroxide (approx. 0.4% NaOH) (1 ml) and water (9 ml) (high-pressure liquid chromatography grade). The solution obtained by this procedure were found to be stable for at least 6 months in refrigerator at 4ᵒC.

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Chemical name of vehicle (organic solvent, emulsifier or dispersant):NaOH and water was used as a vehicle.

Test organisms (species):

Staphylococcus aureus

Details on inoculum:

- Laboratory culture: The test organism S. aureus ATCC 13565 was obtained from American Type Culture Collection, Manassas, Va.

- Method of cultivation: For the study, a 300-µl aliquot of dye solution (1 mg/ml) was mixed with 0.7 ml of BHI and then added to a tube of diluted culture. The tubes were aerated vigorously, and the OD was measured every 45 min to check culture growth. The survival rate was measured by plating serial dilutions of a sample taken during the experiment on BHI plates.

- Preparation of inoculum for exposure: For inoculum preparation, brain heart infusion broth (BHI) was used. Cultures were incubated shaking (200 rpm) at 37°C. All the experiments were conducted under conditions of standard room illumination (fluorescent ceiling light, Sylvania Octron 4100K) in tubes containing 3 ml of medium. Growth was analyzed by measuring turbidity (absorbance at a wavelength of 660 to 680 nm) with a
spectrophotometer (Spectronic 21D). Experiments were initiated with ̴0.2 ml of inoculum from a fresh culture grown aerobically at an optical density (OD) of ̴1. Colony counts were measured on BHI plates.

Test type:

not specified

Water media type:

freshwater

Total exposure duration:

250 min

Post exposure observation period:

OD was measured every 45 mins to check culture growth.

Hardness:

no data

Test temperature:

no data

pH:

no data

Dissolved oxygen:

no data

Salinity:

no data

Nominal and measured concentrations:

Nominal concentrations

Details on test conditions:

TEST SYSTEM
- Test vessel: Test tubes
- Aeration: The tubes containing the test solutions and cultures were aerated vigorously.
TEST CONCENTRATIONS
- Test concentrations: 100 µg/ml (0.1 mg/ml)

Reference substance (positive control):

not specified

Duration:

250 min

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Remarks on result:

other: The test substance do not have any activity against S. aureus i.e, no difference was observed between the treated test tubes and the control tubes.

Validity criteria fulfilled:

not specified

Conclusions:

As the test substance do not have any activity against S. aureus i.e, no difference was observed between the treated test tubes and the control tubes, the NOEC value was found to be 100 mg/l.

Executive summary:

Toxicity to micro-organisms study was conducted onStaphylococcus aureusof enterotoxigenic strain ATCC 13565. For the preparation of dye solution, a test portion (approximately 10 mg) was placed in a 10-ml volumetric flask, which was wrapped in aluminum foil, and dissolved by adding aqueous sodium hydroxide (approx. 0.4% NaOH) (1 ml) and water (9 ml).Inoculum was prepared inbrain heart infusion broth (BHI). Cultures were incubated shaking (200 rpm) at 37°C. All the experiments were conducted under conditions of standard room illumination (fluorescent ceiling light, Sylvania Octron 4100K) in tubes containing 3 ml of medium. Growth was analyzed by measuring turbidity (absorbance at a wavelength of 660 to 680 nm) with a spectrophotometer (Spectronic 21D). Experiments were initiated with  ̴0.2 ml of inoculum from a fresh culture grown aerobically at an optical density (OD) of ̴1. Colony counts were measured on BHI plates.

 

For the study,a 300-µl aliquot of dye solution (1 mg/ml) was mixed with 0.7 ml of BHI and then added to a tube of diluted culture. The tubes were aerated vigorously, and the OD was measured every 45 min to check culture growth. The survival rate was measured by plating serial dilutions of a sample taken during the experiment on BHI plates.

 

During the study period of 250 mins, OD was measured every 45 mins to check culture growth.Experiment was performed in triplicate on separate days to ascertain reproducibility.As the test substance do not have any activity againstS. aureusi.e, no difference was observed between the treated test tubes and the control tubes, the NOEC value was found to be 100 mg/l.

Description of key information

Toxicity to microorganism:

Toxicity to micro-organisms study was conducted onStaphylococcus aureusof enterotoxigenic strain ATCC 13565.For the preparation of dye solution, a test portion (approximately 10 mg) was placed in a 10-ml volumetric flask, which was wrapped in aluminum foil, and dissolved by adding aqueous sodium hydroxide (approx. 0.4% NaOH) (1 ml) and water (9 ml).Inoculum was prepared inbrain heart infusion broth (BHI). Cultures were incubated shaking (200 rpm) at 37°C. All the experiments were conducted under conditions of standard room illumination (fluorescent ceiling light, Sylvania Octron 4100K) in tubes containing 3 ml of medium. Growth was analyzed by measuring turbidity (absorbance at a wavelength of 660 to 680 nm) with a spectrophotometer (Spectronic 21D). Experiments were initiated with  ̴0.2 ml of inoculum from a fresh culture grown aerobically at an optical density (OD) of ̴1. Colony counts were measured on BHI plates.

 

For the study,a 300-µl aliquot of dye solution (1 mg/ml) was mixed with 0.7 ml of BHI and then added to a tube of diluted culture. The tubes were aerated vigorously, and the OD was measured every 45 min to check culture growth. The survival rate was measured by plating serial dilutions of a sample taken during the experiment on BHI plates.

 

During the study period of 250 mins, OD was measured every 45 mins to check culture growth.Experiment was performed in triplicate on separate days to ascertain reproducibility.As the test substance do not have any activity againstS. aureusi.e, no difference was observed between the treated test tubes and the control tubes, the NOEC value was found to be 100 mg/l.

Additional information

Toxicity to microorganism:

Toxicity of test material was determined based on the data derived from peer reviewed journals ,

In a journal toxicity to micro-organisms study was conducted onStaphylococcus aureusof enterotoxigenic strain ATCC 13565.For the preparation of dye solution, a test portion (approximately 10 mg) was placed in a 10-ml volumetric flask, which was wrapped in aluminum foil, and dissolved by adding aqueous sodium hydroxide (approx. 0.4% NaOH) (1 ml) and water (9 ml).Inoculum was prepared inbrain heart infusion broth (BHI). Cultures were incubated shaking (200 rpm) at 37°C. All the experiments were conducted under conditions of standard room illumination (fluorescent ceiling light, Sylvania Octron 4100K) in tubes containing 3 ml of medium. Growth was analyzed by measuring turbidity (absorbance at a wavelength of 660 to 680 nm) with a spectrophotometer (Spectronic 21D). Experiments were initiated with  ̴0.2 ml of inoculum from a fresh culture grown aerobically at an optical density (OD) of ̴1. Colony counts were measured on BHI plates.

 

For the study,a 300-µl aliquot of dye solution (1 mg/ml) was mixed with 0.7 ml of BHI and then added to a tube of diluted culture. The tubes were aerated vigorously, and the OD was measured every 45 min to check culture growth. The survival rate was measured by plating serial dilutions of a sample taken during the experiment on BHI plates.

 

During the study period of 250 mins, OD was measured every 45 mins to check culture growth.Experiment was performed in triplicate on separate days to ascertain reproducibility.As the test substance do not have any activity againstS. aureusi.e, no difference was observed between the treated test tubes and the control tubes, the NOEC value was found to be 100 mg/l.

In another study ,toxicity to micro-organisms study was conducted onParamecium caudatumfor 20 mins.The test chemical conc. used for the study was 1000 mg/l (0.1%).The test organismParamecium caudatumwas maintained at22°C on 0.15% dried lettuce infusion and fed withAerobacter aerogenes.Food dye (test chemical) of 0.1% conc. was put in a hollow slide glass, and an equal volume of 0.04 M phosphate buffer, pH 7.0, was added. After 5 to 10Paramecium caudatumwere added, their survival times were measured microscopically. 30 to 40 test organism for each conc. were tested and the mean survival time and the death rate was calculated after 20 mins.

 The survival time was defined as the time required until death was observed for each concentration. Death was assumed to have occurred when there was no movement. The death rate was defined as the percentage of deaths observed during 20 min.

 The mean survival time of test organismParamecium caudatumwas found to be 457 seconds i.e 7.61667 min. Based on mortality, the EC100 value was reported to be 1000 mg/l.

In a data from peer reviewed journal ,toxicity to micro-organisms study was conducted on gram – negative bacteria. Inhibitory activity of test chemical (Eosin Yellowish, Eosin Y)was determined by the traditional agar gel method.The conc. of test chemical used for the study was 0.6918 mg/l (1 µM).

These test organisms were taken from the collection of the Plant Protection Institute, Hungarian Academy of Sciences (Budapest, Hungary).The bacteria were maintained on Nutrient Agar (Oxoid CM3) completed with vitamins pyridoxine.HCl, thiamine. HCl, riboflavine and nicotinamide at 1, 10, 1 and 20 mg/l concentrations. Bacterial suspensions for screening were prepared by washing cells with sterile tap water containing 0.3% peptone from slants of 20 h old cultures grown at (21±1)°C.

 

The culture medium consisted of agar (11 g/l), glucose (5 g/l), peptone (5 g/l), yeast extract (3 g/l), glycerol (2 g/l), Na-β-glycerophosphate.6H2O (0.5 g/l), KH2PO4 (0.5 g/l), Na2HPO4.7H2O (0.5 g/l), KCl (0.25 g/l), MgSO4 (0.15 g/l), CaCl2 (0.15 g/l), FeSO4.5H2O (0.025 g/l), CuSO4.5H2O (0.005 g/l), MnSO4.H2O (0.005 g/l), Ni(NO3)2.6H2O (1 mg/l) and CoCl2.6H2O (1 mg/l), respectively.

 

A layer of 5 mm depth of inoculated medium was dispensed into Petri dishes of 90 mm diameter. Filter paper discs of 5 mm diameter were impregnated with 1µM solution of test compounds and placed centrally on the surface of the agar plate. Growth inhibition zones were measured after 24 h incubation at 21±1°C.After incubation colony diameters were determined and growth inhibition was calculated in percentage of dye free colony growth.Each determination was run in quadruplicate.As no effect on growth of test bacteriaAgrobacterium radiobacter, Escherichia coli, Erwinia atroseptica, Erwinia herbicola, Erwinia uredovoraandPseudomonas phaseolicolawere observed, the NOEC value was found to be0.6918 mg/l.