Isolation of a microorganism capable of degrading poly-(L-lactide).

The isolation of poly-(L-lactide) (PLA)-degrading microorganisms was investigated. A PLA-degrading actinomycete, strain No. 3118, was isolated and tentatively identified as a member of the genus Amycolatopsis. The optimum conditions for degradation of PLA were 43 degrees C at about pH 7 in a mineral salt medium with a low concentration of organic nutrients (0.002% yeast extract). The original shape of PLA film (Mw=2.3x10(5) after sterilization, 20 &mgr;m thick) disappeared within 2 weeks. Lactic acid was detected after the film was incubated with culture supernatant.