[No public or meaningful name is available]

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 October 2017 - 22 November 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Version / remarks:

2006

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Version / remarks:

Regulation (EC) No 440/2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

The chemical oxygen demand (COD) of the test item was determined by an external laboratory following guideline DIN 38414-S9 under the quality system management ISO/IEC 17025; this determination is therefore excluded from the statement of GLP compliance

Test material

Test material information

Constituent 1

Reference substance name:

Fructose-1,6-Diphosphate, raw: Glucose anaerobically fermented by Saccharomyces cerevisiae, concentrated, phosphorylated

Molecular formula:

Molecular formula of the eponymous compound: C6H14O12P2

IUPAC Name:

Fructose-1,6-Diphosphate, raw: Glucose anaerobically fermented by Saccharomyces cerevisiae, concentrated, phosphorylated

Test material form:

solid

Details on test material:

Batch No.: 18224600

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source: Sludge from the aeration tank of the ARA Werdhölzli (CH-8048 Zürich), a municipal biological waste water treatment plant.
- Preparation of inoculum for exposure: The sludge was pre-conditioned for 6 days (aerated but not fed) to reduce the amount of O2 consumed by the blank controls. Therefore, the sludge was washed twice with tap water and once with test medium.
- Pretreatment: The activated sludge was used after sampling from the treatment plant without adaptation.
- Concentration of sludge: 30 mg/L dry matter in the final mixture.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

197 mg/L

Based on:

other: nominal test item concentration based on 100 mg COD/L

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of test medium: Aerobic mineral salts medium prepared with ultrapure water (conductivity: <1.5 µS/cm; DOC: <0.5 mg/L)
* mineral stock solution A (10mL/L): 8.5 g/L KH2PO4, 28.49 g/L K2HPO4.3H2O, 33.4 g/L Na2HPO4.2H2O, 0.5 g/L NH4Cl, pH of stock solution A: 7.4
* mineral stock solution B (1 mL/L): 36.4 g/L CaCl2.2H2O
* mineral stock solution C (1 mL/L): 22.5 g/L MgSO4.7H2O
* mineral stock solution D (1 mL/L): 0.25 g/L FeCl3.6H2O
* Final test medium: 10 mL of solution A and 1 mL of solutions B, C and D per L of test medium

- Test temperature: 22±2°C, controlled at ± 1°C, in a thermostat cabinet in the dark
- pH: 7.4±0.2°C (measured prior to testing and if necessary adjusted with NaOH or HCl (except in flask C).
- Continuous darkness: yes, test bottles were in a thermostat cabinet.

TEST SYSTEM
- Test flasks: 510 mL glass bottles (tightly closed with manometric BOD measuring devices) containing a total volume of test solution of 200 mL. The bottles were equipped with stirring rods and butyl rubber quivers which contain 2 pellets of sodium hydroxide each to absorb the produced CO2 from the head space.
- Test performed in duplicate (two test flasks)

After centrifugation, the sludge was suspended in test medium, at about 2 g/L dry matter. Before the test, this suspension was diluted down to 60 mg/L dry matter, i.e. twice the final concentration, since this suspension was diluted 1:1 (v:v) afterwards. The test item and the reference item were dissolved in the test medium (separately) at a concentration twice of the final concentration to be achieved for the test, and these two respective stock solutions were then diluted 1:1 (v:v) with the sludge suspension to give a final test concentration as COD or ThOD, respectively, of about 100 mg O2/L.

CONTROL AND BLANK SYSTEM
B: Inoculum blank (two replicates)
R: Procedure control (two replicates): 60.0 mg/L Sodium benzoate (99.9 mg ThOD/L)
C: Abiotic sterile control (one replicate): 197 mg/L test item (99.6 mg COD/L)
X: Toxicity control (one replicate): 197 mg/L test item and 60.0 mg/L reference item (total 200 mg oxygen demand/L)

SAMPLING
The test vessels were stirred by an inductive stirring system for a maximum test period of 28 days. During the test the O2 uptake was continuously measured with a manometric BOD measuring device. Temperature was recorded with a data logger.
At the end of the test, the pH was measured in all flasks except the abiotic sterile control (C), and the DOC content was determined in flasks T, B and R.

STATISTICAL METHODS:
Values of % degradation were calculated for each test flask and day. The arithmetic mean of % degradation in each test flask on each day was calculated.

Reference substance

Reference substance:

other: Sodium benzoate

Remarks:

CAS 532-32-1

Results and discussion

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

87

Sampling time:

28 d

Remarks on result:

other: test flask 1 after 28 d: 87.7% test flask 2 after 28 d: 85.7%

Details on results:

The biodegradability of Fructose-1,6-Diphosphate, raw: Glucose anaerobically fermented by Saccharomyces cerevisiae, concentrated, phosphorylated based on O2 consumption (mineralisation) was calculated to be 87% after 28 days as compared to the chemical oxygen demand (COD). The biodegradation reached 70% at the end of the 10-d window (i.e. within 10 days after attainment of 10% degradation). Biodegradation of the test item started without any significant lag-phase.
The respective concentrations of organic carbon at the beginning (as mg DOC/L ; measured in the stock solution) and at the end of the test (mean measured value of the two replicates), respectively, were:
- 39.8 and 2.07 for the test units (mean of two replicates)
- <0.5 and 0.78 for the blank control (mean of two replicates)
- 38.2 and 1.24 for the procedure control (mean of two replicates)
The total elimination calculated based on the determination of the dissolved organic carbon (DOC) at the end of the test reached 97% for Fructose-1,6-Diphosphate, raw: Glucose anaerobically fermented by Saccharomyces cerevisiae, concentrated, phosphorylated and 99% for sodium benzoate, respectively. This data is in line with the degradation calculated based on O2 consumption.

Fructose-1,6-Diphosphate, raw: Glucose anaerobically fermented by Saccharomyces cerevisiae, concentrated, phosphorylated (EC no. 944-754-7) reached the pass level of 60% mineralisation in the Manometric Respirometry Test within the 10-d window and, therefore, can be termed as readily biodegradable.

Any other information on results incl. tables

Procedure control:

The procedure control sodium benzoate reached a biodegradation of 88% (mineralisation) after 14 days, thus confirming suitability of inoculum and test conditions.

Toxicity control:

At the applied initial test concentration of 197 mg/L the test item was not judged to have any inhibitory effect on the microbial population, since the biodegradation of the mixture (test item + reference item sodium benzoate) exceeded 25% within 14 days.

Abiotic steril control:

Fructose-1,6-Diphosphate, raw: Glucose anaerobically fermented by Saccharomyces cerevisiae, concentrated, phosphorylated was not abiotically degraded (by processes using O2) during the whole test period of 28 days in the absence of microorganisms as confirmed by the lack of oxygen consumption

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

A 28-d ready biodegradability test (OECD 301F, Manometric Respirometry Test) using activated sludge of a municipal sewage treatment plant indicated that Fructose-1,6-Diphosphate, raw: Glucose anaerobically fermented by Saccharomyces cerevisiae, concentrated, phosphorylated (EC 944-754-7) reached a biodegradation of 87% based on O2 consumption. The substance reached the pass level of 60% for ready biodegradability in the Manometric Respirometry Test within the 10-d window and, therefore, can be termed as readily biodegradable.

Executive summary:

The biodegradability of Fructose-1,6-Diphosphate, raw: Glucose anaerobically fermented by Saccharomyces cerevisiae, concentrated, phosphorylated (EC no. 944-754-7) exposed to microorganisms derived from activated sludge of a municipal sewage treatment plant was investigated under aerobic static exposure conditions, following the test guideline OECD 301 F.

Both the mineralisation over the course of the test (based on O2 consumption) and the total elimination at the end of the test (based on the determination of the dissolved organic carbon, DOC) were assessed.

The biodegradability of Fructose-1,6-Diphosphate, raw: Glucose anaerobically fermented by Saccharomyces cerevisiae, concentrated, phosphorylated based on O2 consumption (mineralisation) was calculated to be 87% after 28 days as compared to the chemical oxygen demand (COD).

The biodegradation reached 70% at the end of the 10-d window (i.e. within 10 days after attainment of 10% degradation). 

Biodegradation of the test item started without any significant lag-phase.

The procedure control sodium benzoate reached a biodegradation of 88% (mineralisation) after 14 days, thus confirming suitability of inoculum and test conditions.

The total elimination calculated based on the determination of the dissolved organic carbon (DOC) at the end of the test reached 97% for Fructose-1,6-Diphosphate, raw: Glucose anaerobically fermented by Saccharomyces cerevisiae, concentrated, phosphorylated and 99% for sodium benzoate, respectively. This data is in line with the degradation calculated based on O2 consumption.

Fructose-1,6-Diphosphate, raw: Glucose anaerobically fermented by Saccharomyces cerevisiae, concentrated, phosphorylated (EC no. 944-754-7) reached the pass level of 60% mineralisation in the Manometric Respirometry Test within the 10-d window and, therefore, can be termed as readily biodegradable.

All validity criteria were fulfilled.