Peng Yu-Huei, Shih Yang-hsin, Lai Yen-Chun, Liu Yuan-Zan, Liu Ying-Tong, Lin Nai-Chun
Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 106, Taiwan, China.
Environ Sci Pollut Res Int. 2014;21(16):9529-37. doi: 10.1007/s11356-014-2647-8. Epub 2014 Mar 15.
The increasing usage and the persistence of polyester polyurethane (PU) generate significant sources of environmental pollution. The effective and environmental friendly bioremediation techniques for this refractory waste are in high demand. In this study, three novel PU degrading bacteria were isolated from farm soils and activated sludge. Based upon 16S ribosomal RNA gene sequence blast, their identities were determined. Particularly robust activity was observed in Pseudomonas putida; it spent 4 days to degrade 92% of Impranil DLN(TM) for supporting its growth. The optimum temperature and pH for DLN removal by P. putida were 25 °C and 8.4, respectively. The degradation and transformation of DLN investigated by Fourier transformed infrared spectroscopy show the decrease in ester functional group and the emergence of amide group. The polyurethanolytic activities were both presented in the extracellular fraction and in the cytosol. Esterase activity was detected in the cell lysate. A 45-kDa protein bearing polyurethanolytic activity was also detected in the extracellular medium. This study presented high PU degrading activity of P. putida and demonstrated its responsible enzymes during the PU degradation process, which could be applied in the bioremediation and management of plastic wastes.
聚酯聚氨酯（PU）使用量的不断增加及其持久性产生了大量的环境污染源。对于这种难降解废物，迫切需要有效且环保的生物修复技术。在本研究中，从农田土壤和活性污泥中分离出三种新型的PU降解细菌。基于16S核糖体RNA基因序列比对，确定了它们的身份。在恶臭假单胞菌中观察到特别强的活性；它花费4天时间降解了92%的Impranil DLN(TM)以支持其生长。恶臭假单胞菌去除DLN的最适温度和pH分别为25℃和8.4。通过傅里叶变换红外光谱研究DLN的降解和转化，结果表明酯官能团减少，酰胺基团出现。聚氨酯分解活性在细胞外部分和胞质溶胶中均有表现。在细胞裂解物中检测到酯酶活性。在细胞外培养基中还检测到一种具有聚氨酯分解活性的45 kDa蛋白质。本研究展示了恶臭假单胞菌对PU的高降解活性，并证明了其在PU降解过程中的相关酶，这可应用于塑料废物的生物修复和管理。
