Lysozyme (chicken egg white)

Biodegradation in water: screening tests

Description of key information

Readily biodegradable

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

The general degradation pathway of proteins is a stepwise process starting with the splitting of peptide bonds in the protein polymer by proteolytic enzymes (proteases) forming lower-molecular oligopeptides, which are subsequently degraded by peptidases to the monomeric amino acids. Physical effects like heating, dilution, mixing of solutions with air, etc. lead to denaturation, i.e. loss of activity and changes of the three-dimensional structure, which facilitates this proteolytical degradation process^[1].

Literature data available on other enzymes confirm that this type of substances are readily biodegradable:

Lipase

-OECD 301 E; 99% DOC remove. Ready biodegradable^{[1 -2]}

Cellulase

- OECD 301 E, 84% DOC removal. Ready biodegradable^{[1 -2]}

- OECD 301 C, 78% BOD/COD.^{[1 -3]}

Amylase

- OECD 301 E, 99% DOC removal^{[1 -2]}

-OECD 301 E, 99% DOC removal^{[1 -2]}

Subtilisin

-Studies available on biodegradation showed that there is no significant difference in the biodegradation rate and extent between wild type Subtilisins and protein engineered variants. This is in line with the general understanding of the common structure and properties of proteins irrespective of their specific activity pattern and their origin. Consequently, the exposure assessment of Subtilisins does not need to differentiate between wild type and protein engineered enzyme.^[4]

Reference

[1] HERA Human and environmental risk assessment on ingredients of household cleaning products - alpha-amylases, cellulases and lipases. 2005.

[2] Bergman A, Bak J, Stavnsbjerg M (1997). Environmental fate of detergent enzymes. In: International Symposium Environmental Biotechnology. Oostende, Belgium. Part 2, 303-305. Edited by H. Verachtert & W. Verstraete. ISBN 90-5204-031-1

[3] Greenough RJ, Everett DJ (1991) Safety evaluation of alkaline cellulase. Food and Chemical Toxicology 29: 781-785.

[4] HERA Human and environmental risk assessment on ingredients of household cleaning products - Subtilisins (Proteases). Edition 2.0. 2007.