Enzymatic Hydrolysis of Polylactic Acid Fiber

Abstract

This study investigated the optimization of the enzymatic processing conditions for polylactic acid (PLA) fibers using enzymes consisting of lipases originating from different sources. The hydrolytic activity was evaluated taking into consideration the pH, temperature, enzyme concentration, and treatment time. The structural change of the PLA fibers was measured in the optimal treatment conditions. PLA fiber hydrolysis by lipases was maximized for lipase from Aspergillus niger at 40 °C for 60 min at pH 7.5 with 60% (owf) concentration, for lipase from Candida cylindracea at 40 °C for 120 min at pH 8.0 with 70% (owf) concentration, and for lipase from Candida rugosa at 45 °C for 120 min at pH 8.0 with 70% (owf) concentration. There was a change in protein absorbance of the treatment solution before and after all lipase treatments. The analyses of the chemical structure change and structural properties of the PLA due to lipase treatment was confirmed by tensile strength, differential scanning calorimetry, wide-angle X-ray scattering diffractometry, Fourier transform infrared spectroscopy, and scanning electron microscopy.

A Comparative Study on the Mechanical, Thermal and Morphological Characterization of Poly(lactic acid)/Epoxidized Palm Oil Blend

“…PLA, a linear aliphatic polyester, is considered as the most innovative alternatives for conventional petroleum-based polymers because it has similar mechanical properties such as density, glass transition temperature (T g ), tensile strength, and Young’s modulus as to those of PET [7]. Furthermore, PLA has good potential due to its excellent properties, such as good mechanical properties (especially in strength and modulus), easy processability, excellent degradability and transparency [3].…”

Thermal hydrolysis of poly(l‐lactic acid) films and cytotoxicity of water‐soluble degradation products

“…26 To obtain the water-soluble degradation products of PLLA, hydrolysis is a simple way and includes thermal hydrolysis, acid hydrolysis, alkali hydrolysis, and enzymatic hydrolysis. [27][28][29] In comparison to other types of hydrolysis, thermal hydrolysis can better reflect the real degradation of PLLA in food packaging. In this study, thin PLLA films with a thickness of 150 lm approximate to the thickness of commercial beverage bottles were chosen for thermal hydrolysis.…”

Non‐selective hydrolysis of tuna fish oil for producing free fatty acids containing docosahexaenoic acid

“…Enzymatic methods are largely preferred over conventional chemical methods because of the reduced cost of solvents, high enzyme specificity especially lipases and ease of reaction . Lipases (EC 3.1.1.3 triacylglycerolacyl hydrolyase) can catalyse both the hydrolysis and esterification reactions of oils/fatty acids with a reasonable rate, depending upon the type of lipase such as Candida rugosa , Candida antarctica , Pseudomonas , Mucor miehei , Rhizopus oryzae , etc . For the enrichment of DHA and EPA, lipase catalysed hydrolysis of oil is reported as the first step to release free fatty acids from the breakdown of ester bonds of triglycerides in fish oil.…”

“…C. antarctica lipase‐B has been categorised as a highly selective lipase because it has a very narrow and deep substrate binding site in the range of 10 Å × 4 Å wide and 12 Å deep in comparison to other lipases. This small space inside the binding site causes only very specific substrate to bind with it and hence results into a high degree of selectivity . According to the work of Uppenberg et al, hydrolysis with lipases can be carried out by both selectively and non‐selectively depending upon the nature and overall shape of the acyl‐chain binding active site in lipases.…”

“…[17][18][19] Lipases (EC 3.1.1.3 triacylglycerolacyl hydrolyase) can catalyse both the hydrolysis and esterification reactions [20,21] of oils/fatty acids with a reasonable rate, depending upon the type of lipase such as Candida rugosa, Candida antarctica, Pseudomonas, Mucor miehei, Rhizopus oryzae, etc. [22][23][24][25] For the enrichment of DHA and EPA, lipase catalysed hydrolysis of oil is reported as the first step to release free fatty acids from the breakdown of ester bonds of triglycerides in fish oil. C. antarctica lipase-B has been categorised as a highly selective lipase because it has a very narrow and deep substrate binding site in the range of 10 Å Â 4 Å wide and 12 Å deep in comparison to other lipases.…”