Production of poly(l-lactide)-degrading enzyme by Amycolatopsis orientalis for biological recycling of poly(l-lactide)

Abstract

Efficient production of poly(L-lactide)(PLA)-degrading enzyme was achieved by addition of 0.1% (w/v) silk fibroin powder into a liquid culture medium of an actinomycete, Amycolatopsis orientalis, without other complex nitrogen sources, such as yeast extract and peptone. Scaled-up production of the enzyme in a 5-l jar fermenter showed the possibility of producing this enzyme on an industrial scale at low production cost. The extracellular PLA-degrading enzyme showed potent degrading activity, which is effective for biological recycling of PLA, i.e., 2,000 mg/l of PLA powder was completely degraded within 8 h at 40 degrees C using 20 mg/l purified enzyme. An optically active L-lactic acid with 600 mg/l was obtained as degradation product of PLA without undesirable racemization.

The environment shapes microbial enzymes: five cold-active and salt-resistant carboxylesterases from marine metagenomes

“…However, the lipase-like proteins (esterase family I) PlaM4, PlaM7 and PlaM9 from a compost metagenome, as well as PlaA from Paenibacillus amylolyticus, were found to exhibit degradation activities towards PLA and several other polyesters including PCL, PBSA, poly(butylene succinate) (PBS) and poly(ethylene succinate) (PES) Mayumi et al 2008). Our work has revealed that in addition to the previously identified lipases and proteases (Jarerat et al 2006;Matsuda et al 2005), proteins from several esterase families including the β-lactamase-like enzymes (family VIII) show high hydrolytic activity against PLA and other polyester substrates. Thus, the metagenomic esterases exhibit different substrate preferences and show activity against a broad range of monoester and polyester substrates including PLA.…”

A novel poly (L-lactide) degrading actinomycetes isolated from Thai forest soil, phylogenic relationship and the enzyme characterization

“…The liberation of p-nitroaniline (pNA) from the respective substrates was spectrophotometrically monitored at 410 nm. Gelatinase and caseinase activities were assayed in 0.1 M glycine-NaOH buffer (pH 10.0) at 70 C for 10 min using gelatin and casein, according to a modifi ed method of Jarerat et al (2006). The reaction of gelatinase was terminated by adding 5 ml of HgCl 2 acid solution.…”

Characterization of poly(L-lactide)-degrading enzyme produced by thermophilic filamentous bacteria Laceyella sacchari LP175

“…Poly(L-lactide) (PLLA); (C 3 H 4 O 2 )n is one of the aliphatic biodegradable polyesters derived from renewable resources such as corn, cassava, sugar cane, rice and potato through lactic acid fermentation, and it is also fully degradable by both microbial and enzymatic processes (Tokiwa et al, 2009;Gupta et al, 2007;Jarerat et al, 2006;Tokiwa and Calabia, 2006;Tomita et al, 2004). PLLA, as an environmentally friendly (eco-friendly or green ) product, has been developed on a large scale and is currently used for a wide range of applications, including packaging materials (Bhalla et al, 2007;Nolan-Itu Pty Ltd., 2002), medical applications (Jalil, 1990), agricultural products (Gross and Kalra, 2002;Sakai et al, 2001) and textiles.…”