Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

The toxicity of xanthan lyase to aquatic organisms has not been tested, however, a read-across was performed with other enzymes belonging to different enzyme classes, namely alpha amylase, cellulase, glycoamulase, peroxidase, and asparaginase. Due to the similarity between the enzymes, similar results are expected for pectin lyase.

The lowest EC50 5.2 mg aep/L was seen when testing alpha-amylase on the growth of the unicellular green alga Desmodesmus subspicatus.

Additional information

The physico-chemical properties of enzymes including logPow are very similar . They are proteins built up of amino acids and the type, order and number of the amino acids in the polymer differs between enzymes, determining the 3-dimensional structure, the activity and specificity of the individual enzyme type. Because all enzymes are built up of the same amino acids, the physical and chemical characteristics will be very similar for different enzymes and even more similar within the same sub-class. Therefore read-across from other non-proteolytic enzymes should be fully applicable.

Data obtained for alpha-amylase have been used for PNEC derivation because effect of alpha-amylase on algae can be considered worst-case within the tested non-proteolytic enzymes.

Several enzymes from various enzyme classes were tested in aquatic toxicity studies. All studies were conducted according to OECD guidelines and in compliance with GLP.

The unicellular green algae Desmodesmus subspicatus was found to be the most sensitive species for acute effects.

The results from the aquatic studies are following:

OECD guideline 201: unicellular green algae Desmodesmus subspicatus or Pseudokirchneriella subcapitata, 72 hour semi-static exposure

Test substance

ErC50

mg aep/L

NOEC

mg aep/L

Alpha-amylase, PPY5067

5.2

2.6

Cellulase, PPC31776

52.1

≥52.1

Glucoamylase, PPY 24900

>108.4

≥108.4

Peroxidase, PPX 3806

176.6

138

Asparaginase, PPV24743

6.0

0.9

 

OECD guideline 202:Daphnia magna, 48 hour semi-static exposure

Test substance

EC50

mg aep/L

NOEC

mg aep/L

Alpha-amylase, PPY5067

212

106

Cellulase, PPC31776

> 52.1

≥52.1

Glucoamylase, PPY 24900

> 120

120

Peroxidase, PPX 3806

26.2

8.8

Asparaginase, PPV24743

>17.3

17.3