Amnat JareratYutaka TokiwaHideo TanakaC.P.R Co., Ltd.National Institute of Advanced Industrial Science and TechnologyUniversity of TsukubaMahidol University2018-08-202018-08-202006-10-01Applied Microbiology and Biotechnology. Vol.72, No.4 (2006), 726-731017575982-s2.0-33749021065https://repository.li.mahidol.ac.th/handle/20.500.14594/22969Efficient 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°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. © 2006 Springer-Verlag.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyChemical EngineeringImmunology and MicrobiologyMedicineArticleSCOPUS10.1007/s00253-006-0343-4