一株可降解聚己内酯的细菌菌株选育及其生物降解过程

Breeding and Biodegradation of A PCL Degradable Bacterial Strain

从啤酒厂排污口的活性污泥中分离筛选出1株能够产生聚己内酯(PCL)解聚酶的细菌菌株。经显微镜观察其形态、生理生化特性试验及分子生物学手段16S r DNA序列分析比对,鉴定该菌株属于假单胞菌属(Pseudomonas sp.)。液体培养条件下菌株可使PCL膜在72 h内完全降解,通过扫描电子显微镜对降解到不同程度的PCL膜进行表面形态结构观察,结果显示菌株对PCL薄膜的降解是菌株分泌的PCL解聚酶的作用,其降解模式是由薄膜表层平面到深层的立体降解。质谱检测表明降解产物主要为PCL单体与二聚体。

A strain with poly （s-caprolactone） （PCL） degradable ability was isolated from activated sludge which was achieved from sewage disposal plant in the brewery. The strain was identified as Pseudomonas sp. by colony morphology, physiological and 16S rDNA analysis. The PCL film was de- graded completely within 72 h under the condition of liquid culture. The surface structure of PCL films which had been degraded for different days was observed with SEM, and it showed that PCL degradation occurred first in the surface of PCL and then in the deeper area. The main degraded products of the strain were identified as PCL monomer and two polymers by mass spectrometric anal- ysis.