Biodegradation Process of Poly(butylenes succinate) Film by Strain BFM-X1

In order to reveal the degradation process of the poly(butylene succinate) (PBS) film by strain Bionectria sp. BFM-X1(BFM-X1), the degradation property and residue films under different carbon sources were analyzed. Resultrs showed that this strain can efficiently degrade PBS film when using glucose, glycerol, soybean oil or PBS emulsions as the sole carbon source, respectively. Biodegradation of strain BFM-X1 for PBS films experienced four phases. Firstly, the surface of the film became rough. Secondly, some holes appeared on the film. Then the film disintegrated gradually. Finally, it degraded totally. Especially there was a lag phase at the beginning of the degradation. The degradation rate was fast when glucose existed as the carbon source. The mycelia of strain BFM-X1 could grow and expand on the surface of PBS film, which was a precondition for the degradation of PBS film by this strain. Parasitism of fugal strain was the main power during in the early degradation stage. During degradation，extracellular enzymes catalyzed the hydrolysis of ester bonds on the polymer backbone, and then polymeric compound was spitted to simpler chemical compounds which could be assimilated and absorbed by the microorga-nisms. When these two degradation mechanisms worked together, strain BFM-X1 preferentially degraded an amorphous part of the film from the surface.