Mannanase, endo-1,4-β-

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 August 2000 - 7 February 2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Test solutions for the study were prepared by adding the test substance to a volumetric flask containing about 300 mL of water from the test tank. The flask contents were shaken to ensure a homogeneous solution. The content was then decanted into the test tank and stirred to ensure adequate mixing. The l tank had 20 L of test solution and test water for the test solutions and control, respectively. 10 rainbow trout were added to each tank within 30 min of preparation. Fish were transferred to freshly prepared solutions at 24 h intervals.
- Controls: Test water

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Strain: Oncorhynchus mykiss
- Source: Selcoth Fish Farm, Moffat
- Length at study end (length definition, mean, range and SD): 4-6 cm
- Feeding during test: no

ACCLIMATION
- Acclimation period: at least 12 days
- Acclimation conditions (same as test or not): During holding fish were fed on a suitable standard fish diet. The fish were not fed for the period 24h before the commencement of the test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

64-68 mg/L as CaCO3

Test temperature:

14.5-14.8°C

pH:

6.46-7.28

Dissolved oxygen:

78.8-90.4 % air saturation value

Salinity:

-

Nominal and measured concentrations:

nominal: 100 mg TOS/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass aquarium
- Material, size, fill volume: moulded glass, 25L capacity, 20L volume
- Aeration: yes
- Renewal rate of test solution (frequency): daily
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted fresh water prepared at Inveresk. The water was prepared by addition of salts to high quality water (reverse osmosis grade)
- Conductivity: 174 -199.8 µS
- Culture medium different from test medium: no


EFFECT PARAMETERS MEASURED (with observation intervals if applicable): The fish were observed at 0, 1, 3, 6 and 24h and hereafter daily up to 96h.
At the termination of the limit test, the length (from the tip of the snout to the caudal puncture) and weight of each surviving fish was recorded.

TEST CONCENTRATIONS
- Limit test: 105.8 mg enzyme concentrate dry matter/L

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 105.8 mg/L

Nominal / measured:

nominal

Conc. based on:

other: enzyme concentrate dry matter

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

105.8 mg/L

Nominal / measured:

nominal

Conc. based on:

other: enzyme concentrate dry matter

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: No
- Mortality of control: One fish died as a result of aggressive behaviour of a dominant fish.
- Other adverse effects control: No unusual behaviour was exhibited by all other fish during the test and all appeared healthy and active througout.

Validity criteria fulfilled:

not specified

Conclusions:

Under the conditions of the test, Mannanase, batch PPE6432 was not found to be acutely toxic to rainbow trout (Oncorhynchus mykiss). Consequently, the 96-hour LC50 value for mannanase could not be calculated and must be > 105.8 mg enzyme concentrate dry matter/L (equivalent to 55.5 mg active enzyme protein/L). The "no-observed effect concentration" was the highest concentration 105.8 mg enzyme concentrate dry matter/L (equivalent to 55.5 mg active enzyme protein/L).

Executive summary:

The acute toxicity of Mannanase, batch PPE6432 to rainbow trout (Oncorhynchus mykiss) was assessed by conducting a limit test at nominal concentration of 105.8 mg enzyme concentrate dry matter/L. The study was conducted over a 96-h period under semi-static conditions with the solutions renewed at 24h intervals througout the the test period. The study was performed according to OECD 203 (1992) and in compliance with GLP.

One test tank at 105.8 mg enzyme concentrate dry matter/L and one control tank were included in the test. Ten rainbow trout were added to each tank. Water quality parameters (pH, temperature, conductivity and dissolved oxygen concentration) were measured at the beginning and at 24h intervals in all tanks. All test solution prameters remained within acceptable limits.

No mortalities or other adverse effects were recorded in the test tank througout the study period. In the control tank one fish died as a result of aggressive behaviour by a dominant fish. The results indicate that Mannanase, batch PPE6432 at 105.8 mg enzyme concentrate dry matter/L had no effect on the survival of rainbow trout over a 96 -hr period in semi-static conditions.

It is concluded that the LC50 of Mannanase, batch PPE6432 to rainbow trout is greater than 105.8 mg enzyme concentrate dry matter/L (equivalent to 55.5 mg active enzyme protein/L). The no observed effect concentration is concluded to be the highest concentration tested 105.8 mg enzyme concentrate dry matter/L (equivalent to 55.5 mg active enzyme protein/L).

Description of key information

Under the conditions of the test, Mannanase, batch PPE6432 was not found to be acutely toxic to rainbow trout (Oncorhynchus mykiss). Consequently, the 96-hour LC50 value for mannanase could not be calculated and must be > 105.8 mg enzyme concentrate dry matter/L (equivalent to 55.5 mg active enzyme protein/L). The "no-observed effect concentration" was the highest concentration 105.8 mg enzyme concentrate dry matter/L (equivalent to 55.5 mg active enzyme protein/L).