Alpha,alpha-trehalaseIUBMB 3.2.1.28

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

13-10-2017 to 18-10-2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

A reliability score of 2 was given since the study was not performed under GLP and the concentrations were not measured, but only given as nominal values.

Justification for type of information:

For industrial enzymes, the PNEC (predicted no effect concentration) value for enzymes in general is considered the highest dose tested for a given endpoint in studies conducted and published by the enzyme industry. The one exception is for proteases and oxidoreductases, where effects may be observed at lower concentrations. Similarly, although the daphnia immobilisation study with trehalase was not conducted GLP, the 48-hour effect concentration (LE50) for trehalase was greater than the limit dose of 100 mg/L. The weight-of-evidence indicates that enzymes in general are not ecotoxic.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

Concentrations only given as nominal.

GLP compliance:

no

Remarks:

See 'Justification for type of information'

Analytical monitoring:

no

Details on sampling:

- Concentrations: 6.25, 12.5, 25, 50, 100 mg TOS/L

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Dilution in media (Standard Freshwater ISO 6341).
- Controls: Standard Freshwater ISO6341.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): No

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia
- Strain: Daphnia magna Straus
- Source: MicroBioTests Inc. Daphnia magna have been developed by the research teams at the Laboratory for Biological Research in Aquatic Pollution (LABRAP) at the Ghent University in Belgium.
- Age at study initiation (mean and range, SD): less than 24 hours
- Feeding during test: no

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20-25°C

Nominal and measured concentrations:

6.25, 12.5, 25, 50, 100 mg TOS/L nominal.

Details on test conditions:

TEST SYSTEM
The test was conducted according to DAPHTOXKIT F MAGNA Crustacean Toxicity Screening Test for Freshwater with a test system supplied by MicroBioTests Inc.
http://www.microbiotests.be/SOPs/Daphtoxkit%20magna%20F%20SOP%20-%20A5.pdf

- Test vessel: The bioassays are conducted in disposable multiwell test plates with 30 test wells.
- Type: closed
- Material, size, headspace, fill volume: 10 mL
- Aeration: The Standard Freshwater (ISO medium) must be aerated for at least 15 minutes prior to using it.
- No. of organisms per vessel: 20 (5 daphnia per well)
- No. of vessels per concentration and control (replicates): Each plate is provided with 4 wells for the controls and 4 wells (A,B,C,D) for each toxicant concentration.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: ISO medium, formula according to ISO 6341

Composition :
vial 1 : NaHCO3 (129.5 mg - dissolved in 2 L = 67.75 mg/L)
vial 2 : CaCl2.2H2O (588 mg - dissolved in 2 L = 294 mg/L)
vial 3 : MgSO4.7H2O (246.5 mg - dissolved in 2 L = 123.25 mg/L)
vial 4 : KCl (11.5 mg - dissolved in 2 L = 5.75 mg/L)

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 other: mg TOS/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 22.3 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 other: mg TOS/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 22.3 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Details on results:

Details on results
- Mortality of control: 0
- Other adverse effects control: No
- Abnormal responses: No
- Effect concentrations exceeding solubility of substance in test medium: No
Daphnia were considered to be immobile if they were unable to swim within 15 seconds following gentle touch of the animal with a pin.

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the test, trehalase batch PPT48569 was found not to be toxic to Daphnia magna at a nominal concentration up to 100 mg TOS/L (22.3 mg aep/L) after 48h exposure. Thus, no 48h EC50 could be calculated and must be > 100 mg TOS/L (> 22.3 mg aep/L).

Executive summary:

The purpose of this study was to screen trehalase batch PPT48569 for the test material concentration estimated to immobilise 50% of the Daphnia magna after 24 and 48 hours exposure. DAPHTOXKIT F™ magna was supplied by MicroBioTests Inc. The testing of the trehalase batch PPT48569 was performed as a screening with a broad range of concentrations 6.25, 12.5, 25, 50, 100 mg TOS/L. The acceptance criterion for a valid test is that the spontaneous immobility in the control is below or equal to 10%.

Under the conditions of the test, trehalase batch PPT48569 was found not to be toxic to Daphnia magna at a nominal concentration up to 100 mg TOS/L (22.3 mg aep/L) after 48h exposure. Thus, no 48h EC50 could be calculated and must be > 100 mg TOS/L (> 22.3 mg aep/L). NOEC is 22.3 mg aep/L.

Description of key information

Under the conditions of the test, trehalase batch PPT48569 was found not to be toxic to Daphnia magna at a nominal concentration up to 100 mg TOS/L (22.3 mg aep/L) after 48h exposure. Thus, no 48-h EC50 could be calculated and must be > 100 mg TOS/L (> 22.3 mg aep/L). NOEC is 22.3 mg aep/L.