Triggering Degradation of Cellulose Acetate by Embedded Enzymes: Accelerated Enzymatic Degradation and Biodegradation under Simulated Composting Conditions

A green strategythat significantly accelerates the biodegradationrate of cellulose acetate (CA) by triggering deacetylation was demonstrated.Lipase isolated from Candida rugosa was immobilized on CA particles (immobilized lipase (IL)) by a physicalentrapment method and further incorporated in CA films. After 40 daysof aging in contact with external enzymes (lipase and cellulase),the number-average molecular weight (M (n)) of CA/IL 5% decreased by 88%, while the M (n) of CA only exhibited a 48% reduction. Fourier transform infraredand nuclear magnetic resonance spectroscopy of CA/IL 5% indicatedsignificant deacetylation, which was further supported by the decreaseof the water contact angle from 59 to 16 & DEG;. These drastic changeswere not observed for CA. Similar differences in the degradation ratewere observed during aging under simulated composting conditions.After 180 days of simulated composting, traces of CA/IL 5% were barelyobservable, while large pieces of CA still remained. This could openthe door to modified lignocellulose materials with retained biodegradability,also reducing the requirements for the degradation environment asthe process is initiated from inside of the material.

Automated summary

A green strategy was demonstrated to accelerate the biodegradation rate of cellulose acetate (CA) through deacetylation. The immobilization of lipase from Candida rugosa on CA particles resulted in significant deacetylation, as evidenced by changes in molecular weight and water contact angle. This approach showed promising potential for developing modified lignocellulose materials with retained biodegradability.