Polyethylene (CHEBI:60034) consists of long chain polymers of ethylene and it is produced as either high-density (HD-PE) or low-density polyethylene (LD-PE). PE is chemically synthesized by polymerization of ethane and is highly variable, since side chains can be obtained depending on the manufacturing process. Such modifications mainly have influence on crystallinity and molecular weight. The polymer is most frequently used in the packaging industry as one of the main packaging materials, and more than 100 million tons of PE are produced globally per year. Possible PE degradation has been affiliated with a surprisingly large number of bacterial genera. Among those were Gram-negative species affiliated with the genera Pseudomonas, Ralstonia, and Stenotrophomonas but also many Gram-positive taxa. In addition insect guts and their microbiota are explored as possible source for PE degradation. However no convincing biochemical data were generated that have identified defined enzymes and pathways.

Only four enzymes are proposed to act in an oxidative but random manner on the polymer with very low efficiency. However, recently one of these enzymes was shown to exhibit no activity on PE (Stepnov et al., 2024). In our opinion, this finding makes it unlikely that the enzyme “Demetra” featured in the same publication exhibits activity on PE. Thus, we have removed the two enzymes featured in the recent publication of Sanlouis-Verdes et al. (2022).

In case you are aware of other PE-active and partially biochemically or strcturally characterized enzymes, please contact the PAZY team.

Cite: Buchholz, P.C.F., Feuerriegel, G., Zhang, H., Perez-Garcia, P., Nover, L.-L., Chow, J., Streit, W.R. and Pleiss, J (2022);
Plastics degradation by hydrolytic enzymes: The Plastics-Active Enzymes Database - PAZy
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¹ Treatment of PE with LMC02 and LMC03 resulted in release of mainly carboxylic acids (C8-C18) and small amounts of alkanes (C12-C30), 2-ketones (C11-C19) and alcohols (C10).