Polylactic acid (PLA)

Polylactic acid is a synthetic polymer based on renewable sources (D-, L-lactic acid). It is a bio-degradable polymer and it is often known as poly(lactic acid) or polylactide (abbreviation PLA). PLA is a thermoplastic polyester . The enzymatic degradation is slow and depends on the type of copolymer, degree of crystallinity and additives. The polymer C(CH₃)(OH)HCOOH is synthesized by condensation of lactic acid. PLA is in part used as a replacement for some of the fossil-fuel based synthetic polymers.

While in general it is accepted that the ester bonds within the polymer are attacked by esterases and other serine-like hydrolases, only relatively few enzymes have been biochemically characterized in detail. Tough some enzmes are availabe as commercial products. Mainly bacteria and fungi are known act on the polymer. A selection of known enzymes are listed below:

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
(download link for reference manager)