An efficient magnetically modified microbial cell biocomposite for carbazole biodegradation
1 State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People’s Republic of China
2 Present address: State Key Laboratory of Microbial Metabolism, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
Nanoscale Research Letters 2013, 8:522 doi:10.1186/1556-276X-8-522Published: 11 December 2013
Magnetic modification of microbial cells enables to prepare smart biocomposites in bioremediation. In this study, we constructed an efficient biocomposite by assembling Fe3O4 nanoparticles onto the surface of Sphingomonas sp. XLDN2-5 cells. The average particle size of Fe3O4 nanoparticles was about 20 nm with 45.5 emu g-1 saturation magnetization. The morphology of Sphingomonas sp. XLDN2-5 cells before and after Fe3O4 nanoparticle loading was verified by scanning electron microscopy and transmission electronic microscopy. Compared with free cells, the microbial cell/Fe3O4 biocomposite had the same biodegradation activity but exhibited remarkable reusability. The degradation activity of the microbial cell/Fe3O4 biocomposite increased gradually during recycling processes. Additionally, the microbial cell/Fe3O4 biocomposite could be easily separated and recycled by an external magnetic field due to the super-paramagnetic properties of Fe3O4 nanoparticle coating. These results indicated that magnetically modified microbial cells provide a promising technique for improving biocatalysts used in the biodegradation of hazardous compounds.