Degradation of Poly(L-lactide) by a Fungus

Poly(L‐lactide)‐Degrading Activity in Various Actinomycetes

“…[19] The similarity between the stereochemical position of the chiral carbon of the L-lactic acid unit of PLA and the L-alanine unit in the silk polyamide chains was discussed in our previous reports. [3,[10][11][12] The isolated strain of Amycolatopsis used in silk degradation was confirmed to be able to form clear zones on PLA plates. [11] Interestingly, many of the Amycolatopsis strains used in PLA degradation also formed clear zones on the silk plates.…”

“…Further, we found that a fungus strain, Tritirachium album, obtained from American Type Culture Collection (ATCC 22563) could degrade PLA in a liquid medium containing gelatin. [3] PLA-degrading microorganisms have previously been studied by isolating the strains from the natural environment. [4][5][6] We found that microorganisms capable of degrading high-molecularweight PLA are not distributed widely in the environment.…”

A New Method for the Evaluation of Biodegradable Plastic Using Coated Cellulose Paper

“…In comparison to the other published methods of substrate preparation, e.g. plastic powder, [9,15] this method is simpler, faster, and has higher sensitivity and repeatability.…”

“…It is interesting to note that in the degradation by a-chymotrypsin, elastase and trypsin, paper coated by penetration exhibited much higher degradability than powder. It was reported that elastase could not hydrolyze PLA prepared in powder form [9] and that no degradation of PLA film by subtilisin could be detected. [5] Figure 2 shows SEM photographs of the PLA coated cellulose papers prepared by penetration (A) and by adhesion (B) methods (scale bar ¼ 50 mm).…”

“…We pointed out the similarity between the stereochemical position of chiral carbon of L-lactic acid units of PLA and L-alanine units of protein (Figure 4). [9,15,17] It was suggested that a-ester bonds in PLA were susceptible to hydrolysis by these kinds of protease.…”