Breeding Of Pseudomonas Sp.DS0601-fx To Degrade PCL And The Research Of PCL De-polymerase

Poly-caprolactone(PCL) is a biocompatible ,biodegradable and semi- crystalline polyester proposed for a wide variety of applications in the medical industry, extractive industry and environmental protection in recently years. The biodegradability of PCL has been studied but not reported a lot about research of the PCL de-polymerase.The strain DS0601-fx which can degrade PCL efficiently was isolated from the soil . According to morphological observation,the physiological and bio-chemical characteristics and 16S rDNA analysis, the strain was identified to belong to Pseudomonas.The study of the strain growth regulation on the culture medium which use PCL as the sole carbon and energy showed as follows: DS0601-fx can degrade PCL films completely in 70 hours.The trend of the degrade speed is inosculate to the strain growth regulation.Meliorate the proportion of PCL in culture medium which use PCL as the sole carbon and energy source and found DS0601-fx can abundantly produce the PCL de-polymerase in 90 hour by PCL granule medium. An extra-cellular PCL de-polymerase was purified according to gel filtration technique by Sephacryl S-100. The specific activity of the purified enzyme was 14.24-folds and the recovery yield was 2.64%.The degradation of PCL films is studied by SEM photos and found there are some formulae in it .The degradation of PCL happened in the surface layer first then deep-seated place. Synchronously the non- crystalline parts degraded rapidly and the crystalline parts slowly degraded at last.The strain DS0601-fx which can efficient degrade not only PCL but also other biodegradable polyester such as PHB and PLA.