Saccharomyces cerevisiae cell wall, extracted

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21October 2020 to 04 November 2020

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The test item is an UVCB substance made of yeast cell wall which are insoluble components. Therefore a high load rate of the substance is added in water in order to allow the measurement of the dissolved organic carbon.

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Principles of method if other than guideline:

The water solubility of the test item Saccharomyces cerevisiae cell wall, extracted, was determined by measurement of DOC concentration in the centrifugated and filtrated test solutions using TOC analyser. The measured values of DOC are used to calculate the percentage of the soluble organic carbon compared to the total organic carbon of the test item.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Specific details on test material used for the study:

Clear beige powder
Batch AD19K01750
Purity : 100% (UVCB)
Expiry date : 27/07/2021

Key result

Water solubility:

13.1 other: % ww

Conc. based on:

other: Dissolved organic carbon compared to the total organic carbon

Loading of aqueous phase:

10 g/L

Incubation duration:

9 d

Temp.:

20 °C

pH:

3.71 - 3.77

Flask No.	DOC measured in the soluble fraction	Conc. of the test item	TOC  of the test item	Percentage of Soluble Carbon
	[mg/L]	[g/L]	[mg/l]	[%]
1C	660.2	10.0260	4652.1	14.2
2	612.8	10.0600	4667.8	13.1
3	656.7	10.0480	4662.3	14.1
5	635.6	10.0100	4644.6	13.7
6	611.4	10.0900	4681.8	13.1
Mean				13.6
Standard deviation				0.53
RSD				3.9

 

Conclusions:

The dissolved organic carbon content measured in the water was 635,3 mg/L following 9 days of shaking at 20°C of the nominal loading rate 4661.7 mg carbon/L, equivalent to 10 g/L of Saccharomyces cerevisiae cell wall, extracted.

Executive summary:

The water solubility of Saccharomyces cerevisiae cell wall, extracted was determined following the EU method A.6

and OECD 105, and in compliance with GLP.

Since the test item is an UVCB with no single chemical marker that can be readily analysed, the DOC (Dissolved Organic Carbon) method was used. The results of preliminary tests have demonstrated that a nominal loading rate above 2 g/L ensures the highest measurable carbon content. So 5 parallel flasks at the loading rate of 10 g/L were prepared and agitated at 20°C during 9 days that is the duration to reach the plateau, with less than 15% difference in DOC values and no upward tendency observed between day 7 and 9. Consequently, the water solutions, recovered at day 9, following a centrifugation (6000 rpm; 10 min.) and a filtration (0.2 µm PTFE) were analysed for their dissolved organic carbon (DOC) concentrations.

The mean of the dissolved organic carbon (DOC) measured in the water was 635,3 mg/L obtained after 9 days of shaking at 20°C of the nominal loading rate of 4661.7 mg carbon/L, equivalent to 10 g/L of Saccharomyces cerevisiae cell wall, extracted.

The percent of soluble part of carbon compared to the TOC of the test item “Saccharomyces cerevisiae cell wall, extracted” represents 13.6 ± 0.53 % at 20°C, corresponding to a relative standard deviation of 3.9%.

Description of key information

The dissolved organic carbon content measured in the water was 635,3 mg/L following 9 days of shaking at 20°C of the nominal loading rate 4661.7 mg carbon/L, equivalent to 10 g/L of Saccharomyces cerevisiae cell wall, extracted.

Key value for chemical safety assessment

at the temperature of:

20 °C

Additional information

The water solubility of Saccharomyces cerevisiae cell wall, extracted was determined following the EU method A.6 and OECD 105, and in compliance with GLP.

Since the test item is an UVCB with no single chemical marker that can be readily analysed, the DOC (Dissolved Organic Carbon) method was used. The results of preliminary tests have demonstrated that a nominal loading rate above 2 g/L ensures the highest measurable carbon content. So 5 parallel flasks at the loading rate of 10 g/L were prepared and agitated at 20°C during 9 days that is the duration to reach the plateau, with less than 15% difference in DOC values and no upward tendency observed between day 7 and 9. Consequently, the water solutions, recovered at day 9, following a centrifugation (6000 rpm; 10 min.) and a filtration (0.2 µm PTFE) were analysed for their dissolved organic carbon (DOC) concentrations.

The mean of the dissolved organic carbon (DOC) measured in the water was 635,3 mg/L obtained after 9 days of shaking at 20°C of the nominal loading rate of 4661.7 mg carbon/L, equivalent to 10 g/L of Saccharomyces cerevisiae cell wall, extracted.

The percent of soluble part of carbon compared to the TOC of the test item “Saccharomyces cerevisiae cell wall, extracted” represents 13.6 ± 0.53 % ww at 20°C, corresponding to a relative standard deviation of 3.9%.