Department of Bioscience and Technology, College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga, Japan.
J Appl Microbiol. 2010 Jun;108(6):1946-53. doi: 10.1111/j.1365-2672.2009.04600.x. Epub 2009 Oct 20.
To degrade ether-type polyurethane (ether-PUR), ether-PUR-degrading micro-organism was isolated. Moreover, ether-PUR-degrading mechanisms were analysed using model compounds of ether-PUR.
A fungus designated as strain PURDK2, capable of changing the configuration of ether-PUR, has been isolated. This isolated fungus was identified as Alternaria sp. Using a scanning electron microscope, the grid structure of ether-PUR was shown to be melted and disrupted by the fungus. The degradation of ether-PUR by the fungus was analysed, and the ether-PUR was degraded by the fungus by about 27.5%. To analyse the urethane-bond degradation by the fungus, a degraded product of ethylphenylcarbamate was analysed using GC/MS. Aniline and ethanol were detected by degradation with the supernatant, indicating that the fungus secreted urethane-bond-degrading enzyme(s). PURDK2 also degraded urea bonds when diphenylmethane-4,4'-dibutylurea was used as a substrate.
The enzyme(s) from PURDK2 degraded urethane and urea bonds to convert the high molecular weight structure of ether-PUR to small molecules; and then the fungus seems to use the small molecules as an energy source.
Ether-PUR-degrading fungus, strain PURDK2, was isolated, and the urethane- and urea-bonds-degrading enzymes from strain PURDK2 could contribute to the material recycling of ether-PUR.
降解醚型聚氨酯（醚 PUR），分离出能够降解醚 PUR 的微生物。此外，还使用醚 PUR 的模型化合物分析了醚 PUR 的降解机制。
已分离出一种能够改变醚 PUR 结构的真菌，命名为 PURDK2 菌株。通过扫描电子显微镜观察，发现该真菌使醚 PUR 的网格结构熔化和破坏。该真菌对醚 PUR 的降解进行了分析，发现真菌将醚 PUR 降解了约 27.5%。为了分析真菌对氨酯键的降解作用，使用 GC/MS 分析了乙基苯基氨基甲酸酯的降解产物。通过上清液的降解，检测到了苯胺和乙醇，表明该真菌分泌了氨酯键降解酶。当使用二苯基甲烷-4,4'-二丁基脲作为底物时，PURDK2 也降解了尿素键。
PURDK2 中的酶可降解氨酯键和尿素键，将醚 PUR 的高分子量结构转化为小分子；然后，真菌似乎将这些小分子用作能源。
分离出了能够降解醚 PUR 的真菌 PURDK2 菌株，并且 PURDK2 菌株中的氨酯键和尿素键降解酶可能有助于醚 PUR 的材料回收。
