For rapid monomerization of biodegradable plastics, various microorganisms were screened and TB-71 was selected as the best strain. TB-71 degraded solid Poly(butylene succinate)-co-(butylene adipate) (PBSA), poly(ethylene succinate), and poly(epsilon-caprolactone) but not poly(butylene succinate), poly(2-hydroxybutylate-co-valerate) or poly(lactic acid). Esterase activity was observed in the culture broth during PBSA degradation, which was specifically induced by PBSA. Analysis of the degradation products revealed that PBSA was degraded to monomers. (C) 2009, The Society for Biotechnology, Japan. All rights reserved.