Saccharides of mannose and galactose from Ceratonia Siliqua seed

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:

March, April 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

The deviation has no incidence on study results.

Principles of method if other than guideline:

N/A

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Saccharides of mannose and galactose from Ceratonia Siliqua seed

IUPAC Name:

Saccharides of mannose and galactose from Ceratonia Siliqua seed

Test material form:

solid: particulate/powder

Details on test material:

- Appearance: beige powder
- Storage: in a dark place at room temperature
- Batch : 14 262
- Manufacturing date: September 19th 2014
- Expiry date: September 19th 2018

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: The inoculum was a fresh sample of activated sludge and was collected from the aeration tank of a sewage treatment plant receiving predominantly domestic sewage.
- Sample site: Water treatment plant "STEP de Lille", 33290 Blanquefort (France) - Tank 2.
- Laboratory culture: A filtration through a fine sieve (about 1 mm) was performed in order to remove coarse particles. After removal of any coarse particles, the sludge was washed by recantation in a mineral medium until sludge was considered free from excess substrate or inhibitor.
- Inoculum preconditioning: Pre-conditioning consisted in aerating sludge (in mineral medium) for 5-7 days before the test and at the test temperature.

Duration of test (contact time):

ca. 28 d

Initial test substance concentration

Initial conc.:

ca. 100 g/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST ITEM PREPARATION:
According to the sponsor, the test item is soluble in water; it was diluted with mineral medium at 1g/L.
Then, this solution, in constant agitation, was directly introduced with sludge into each test vessels. The test item was tested at 100 mg/L in mineral medium.

TEST CONDITIONS
Composition of medium: Mineral medium according to OECD 301F guideline
The test was performed in darkness between 20 to 24°C (constant temperature ±1°C).
- Mineral medium - pH: 7.6
- Inoculum : pH: 6.8, Dissolved oxygen: 9 mg/L, Suspended solids concentration: 2.57 g/L
- Continuous darkness: Yes

TEST SYSTEM
- Culturing apparatus: WTW Oxitop (FCBA reference: ACQU 1030)
- Number of culture flasks/concentration: 3 flasks (test item and inoculum)
- Test performed in closed vessels: Yes
- A measured volume of inoculated medium containing a known concentration of the test item (100 mg/L) as the nominal sole source of Carbon, was stirred in a closed vessel at a constant temperature up to 28 days.
- Details of trap for CO2: Microbial respiration consumes O2 and releases CO2 which were absorbed by soda lime pellets present in the headspace of flasks. This produced a decrease in pressure in the flask proportional to the amount of oxygen taken up by the microbial population during biodegradation
, which was expressed as a percentage of ThOD (Theoretical Oxygen Demand).
- Allowance was made for the endogenous activity of the inoculum by running parallel blanks with inoculum but without the test item. Furthermore, in order to check the procedure, a reference item control (sodium benzoate 60.2 mg/L + inoculum) and toxicity control (sodium benzoate + inoculum + test item) were run in parallel.

SAMPLING
- Sampling frequency: 0 to 28 days

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes; 3 flasks (inoculum only)
- Reference item: 2 flasks (Sodium benzoate and inoculum)
- Toxicity control: Yes; 2 flasks (test item, sodium benzoate and inoculum)

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

Preliminary study:

none

% Degradation

% Degradation 1

Key result

Parameter:

% degradation (O2 consumption)

Remarks:

following the ThOD-NH4

Value:

ca. 86.18

St. dev.:

1.62

Sampling time:

28 d

% Degradation 2

Key result

Parameter:

% degradation (O2 consumption)

Remarks:

following the ThOD-N03

Value:

ca. 82.63

St. dev.:

1.55

Sampling time:

28 d

Details on results:

The test item contains proteins, so nitrogen has been dosed in the elementary analyses, the evaluation of biodegradation had to be based in the following expressed as ThODNH4 and ThODNO3.

Based on ThODNH4, the 10-Day window was reached on Day 6 and the results obtained show that the test item can be considered readily biodegradable after 28 days of incubation with a mean percentage of biodegradation rate 86.18%

Based on ThODNO3, the 10-Day window was reached on Day 6 and the results obtained show that the test item can be considered readily biodegradable after 28 days of incubation with a mean percentage of biodegradation rate 82.63%.

Under conditions of OECD Guideline 301F, the test item, can be considered readily biodegradable based on ThODNO3, assuming nitrification occurs.

Toxicity control:
A biodegradation of 79.01% (with ThODNH4) and 77.29% (with ThODNO3) after 14 days of incubation was noted in the Toxicity control (containing both of the test item and the reference item).
At the end on the test, 28 days of incubation, the results were respectively 86.48% and 84.60%.
Therefore, the test item was not inhibitory at the tested concentration on the aerobic activated sludge micro-organism because degradation was >25% within 14 days (validity criterion).

BOD5 / COD results

Results with reference substance:

The reference item “Sodium benzoate” was degraded up to 83.61% after 14 days.
Therefore, it confirms the suitability of the used aerobic sludge inoculum.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Based on ThODNH4, the 10-Day window was reached on Day 6 and the results obtained show that the test item can be considered readily biodegradable after 28 days of incubation with a mean percentage of biodegradation rate 86.18%.

Based on ThODNO3, the 10-Day window was reached on Day 6 and the results obtained show that the test item can be considered readily biodegradable after 28 days of incubation with a mean percentage of biodegradation rate 82.63%.

Under conditions of OECD Guideline 301F, the test item, can be considered readily biodegradable based on ThODNO3, assuming nitrification occurs.

Executive summary:

The ready biodegradability of the test item has been determined by the Manometric Respirometry Test according to the OECD Guideline No. 301F with GLP compliance.

A measured volume of inoculated medium containing a known concentration of the test item (100 mg/L) as the nominal sole source of Carbon, was stirred in a closed vessel at a constant temperature up to 28 days. Allowance was made for the endogenous activity of the inoculum by running parallel blanks with inoculum but without the test item. Furthermore, in order to check the procedure, a reference item control (sodium benzoate 60.2 mg/L+ inoculum) and toxicity control (sodium benzoate + inoculum+test item) were run in parallel. The amount of oxygen taken up by the microbial population during the biodegradation of the test item (corrected by blank inoculum, run in parallel) was determined from the change in pressure in apparatus and will be expressed as percentage of theoretical Oxygen Demand (ThOD).

The test item contains nitrogen so, Oxygen consumption was studied with nitrification (ThOD_NO3).

Based on ThOD_NH4,the 10-Day window was reached on Day 6 and the results obtained show that the test itemcan be considered readily biodegradableafter 28 days of incubation with a mean percentage of biodegradation rate 86.18%

 Based on ThOD_NO3,the 10-Day window was reached on Day 6 and the results obtained show that the test itemcan be considered readily biodegradableafter 28 days of incubation with a mean percentage of biodegradation rate 82.63%.

Under conditions of OECD Guideline 301F, the test item, can be considered readily biodegradable based on ThOD_NO3, assuming nitrification occurs.