真菌BFM-X1对聚丁二酸丁二醇酯薄膜的降解过程

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

对菌株Bionectriasp.BFM-X1(简称BFM-X1)分别利用不同碳源对聚丁二酸丁二醇酯(PBS)薄膜的降解情况及降解后的残留膜进行了观察分析,揭示PBS薄膜的微生物降解过程。结果表明:菌株分别以PBS乳剂、葡萄糖、大豆油及甘油为唯一碳源时均能有效降解PBS薄膜;降解过程表现为表面失去光泽期、裂纹状结构期、破碎期和完全降解期4个阶段,并存在迟滞期,且葡萄糖碳源下的降解速率快于其他碳源的;菌株的菌丝能在PBS膜表面上扩展生长是该菌株降解PBS的前提,真菌的寄生作用是前期降解的主要动力;降解过程中胞外酶的水解作用使聚合物的酯键水解,生成可被菌株同化吸收的小分子;菌株BFM-X1对PBS薄膜的降解首先发生在膜表面,非结晶部分先于结晶部分被降解。

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 glu cose, 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 wasalag 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 microorganisms. When these two degradation mechanisms worked together, strain BFM-X1 preferentially degraded an amorphous parl of the film from the surface.