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

Abstract

A green strategy that significantly accelerates the biodegradation rate of cellulose acetate (CA) by triggering deacetylation was demonstrated. Lipase isolated from Candida rugosa was immobilized on CA particles (immobilized lipase (IL)) by a physical entrapment method and further incorporated in CA films. After 40 days of 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 infrared and nuclear magnetic resonance spectroscopy of CA/IL 5% indicated significant deacetylation, which was further supported by the decrease of the water contact angle from 59 to 16°. These drastic changes were not observed for CA. Similar differences in the degradation rate were observed during aging under simulated composting conditions. After 180 days of simulated composting, traces of CA/IL 5% were barely observable, while large pieces of CA still remained. This could open the door to modified lignocellulose materials with retained biodegradability, also reducing the requirements for the degradation environment as the process is initiated from inside of the material.

Carbon Dot-Modified Electrospun Cellulose Acetate Mats: Increased Susceptibility to Degradation under Soil Burial and UV Irradiation

“…In the case of the UV-irradiated samples, the char yield decreased for CA-7UV and increased for CA-CD-7UV. These findings are in correlation with earlier studies, where the char yield initially deceased and then increased during, e.g., enzymatic deacetylation and degradation of CA films . There were no large changes in the maximum decomposition temperatures of the different materials, which varied within the range 354–361 °C.…”

“…Biodegradation of CA has been widely studied in different environments, including enzymatic degradation, simulated composting, soil and marine environments, under UV irradiation, and with catalysts to trigger the UV or biodegradation. − Still the knowledge is fragmented due to the complexity of the processes with many variables and the sensitive structure–environment relationships . Furthermore, mineralization as the final stage of biodegradation was often not quantified by monitoring CO 2 emissions .…”

UV Light Degradation of Polylactic Acid Kickstarts Enzymatic Hydrolysis

“…Lipases are present in a high majority of living organisms, with a large number of fungi also producing lipases . Tokiwa et al, demonstrated the ability of lipase to degrade synthetic polyesters, and Alejandra et al, confirmed lipase’s degradation capabilities in poly­(3-hydroxybutyrate- co -4-hydroxybutyrate). , Ultimately, lipase is a readily available enzyme and shown to degrade polyesters. , Figure shows that lipase induces a trend in enzymatic hydrolysis near identical to that of proteinase K. The presence of the identical catalytic triad in both lipase and proteinase K may be the cause for the similar response, with both proteinase K and lipase exhibit the ‘catalytic triad of aspartic acid (Asp), histidine (His), and serine (Ser) . The catalytic triad catalyzes the nucleophilic attack on carbonyl carbons in esters using the active site serine. , While further work exploring wider enzyme structures may yield varied biodegradation capabilities, it is still important that both hydrolases have promoted activity on UV degraded polymers irrespective of individual enzymes.…”

“…35,36 Ultimately, lipase is a readily available enzyme and shown to degrade polyesters. 37,38 Figure 5 shows that lipase induces a trend in enzymatic hydrolysis near identical to that of proteinase K. The presence of the identical catalytic triad in both lipase and proteinase K may be the cause for the similar response, with both proteinase K and lipase exhibit the 'catalytic triad of aspartic acid (Asp), histidine (His), and serine (Ser). 39 The catalytic triad catalyzes the nucleophilic attack on carbonyl carbons in esters using the active site serine.…”

A facile and scalable strategy for fabricating bio-based photodynamic antimicrobial nonwoven eco-textiles

“…The above phenomena were attributed to the hydrolysis and breakage of the C–O–C bonds in the structure, followed by biodegradation under the synergistic action of microorganisms and enzymes. 49…”