Nawaz Ahmed, Hasan Fariha, Shah Aamer A
Department of Microbiology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan.
Department of Microbiology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan
FEMS Microbiol Lett. 2015 Jan;362(1):1-7. doi: 10.1093/femsle/fnu004. Epub 2014 Dec 8.
A poly(ε-caprolactone) (PCL)-degrading bacterium designated as strain MRL-AN1 was isolated from soil. The bacterium was identified as Brevundimonas sp. strain MRL-AN1 through biochemical tests and 16S rRNA gene sequencing. Scanning electron microscopy and Fourier transform infrared spectroscopy results confirmed the degradation of PCL by strain MRL-AN1. An extracellular PCL depolymerase was purified to homogeneity by column chromatography and molecular weight was estimated to be approximately 63.49 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. PCL depolymerase could degrade not only PCL but also other aliphatic polyesters. The enzyme was stable at wide range of temperature (20-45°C) and pH (5-9) as well as stable in the presence of various metal ions, surfactants and organic solvents. Phenylmethylsulfonyl fluoride inhibited enzyme activity that indicates this enzyme belongs to the serine hydrolase family. It is concluded from the results that the enzymes from strain MRL-AN1 might be applied in the process of biochemical monomer recycling in the polyester-contaminated environments.
从土壤中分离出一株名为MRL-AN1的聚（ε-己内酯）（PCL）降解菌。通过生化试验和16S rRNA基因测序，该菌被鉴定为短波单胞菌属MRL-AN1菌株。扫描电子显微镜和傅里叶变换红外光谱结果证实了MRL-AN1菌株对PCL的降解。通过柱色谱法将一种细胞外PCL解聚酶纯化至同质，经十二烷基硫酸钠-聚丙烯酰胺凝胶电泳估计其分子量约为63.49 kDa。PCL解聚酶不仅可以降解PCL，还可以降解其他脂肪族聚酯。该酶在较宽的温度范围（20-45°C）和pH范围（5-9）内稳定，在各种金属离子、表面活性剂和有机溶剂存在的情况下也稳定。苯甲基磺酰氟抑制酶活性，表明该酶属于丝氨酸水解酶家族。结果表明，MRL-AN1菌株产生的酶可能应用于聚酯污染环境中生化单体回收过程。
