In this study, an efficient microbial cell/Fe3O4 biocomposite was constructed by assembling Fe3O4 nanoparticles onto the surface of Sphingomonas sp. XLDN2-5 cells. Figure 1 showed the TEM images of Fe3O4 nanoparticles and their saturation magnetization. The average particle diameter of Fe3O4 nanoparticles was about 20 nm (Figure 1A), and their saturation

magnetization was 45.5 emu · g-1 (Figure 1B), which provided the nanoparticles with super-paramagnetic Selleckchem BYL719 properties. Figure 1 The nature of Fe 3 O 4 nanoparticles. A is the TEM image of Fe3O4 (magnification × 100,000); B is the magnetic curve for Fe3O4 nanoparticles. selleck kinase inhibitor (σs, saturation magnetization; emu, https://www.selleckchem.com/products/qnz-evp4593.html electromagnetic unit; Oe, Oersted). Figure 2 shows

the microbial cells of Sphingomonas sp. XLDN2-5 before and after Fe3O4 nanoparticle loading. The Fe3O4 nanoparticles were efficiently assembled on the surface of the microbial cell because of the large specific surface area and the high surface energy of the nanoparticles as shown in Figure 2B. It was clear that the size of the sorbent was much smaller than that of microbial cell, which was about a few micrometers as shown in Figure 2A. Due to the super-paramagnetic properties of Fe3O4 nanoparticle coating, the microbial cell/Fe3O4 biocomposite could be easily separated and recycled by external magnetic field Florfenicol as shown in Figure 3. When a magnet was touched to the side of a vial containing a suspension of microbial cell/Fe3O4 biocomposite (Figure 3A), the cells aggregated in the region where the magnet touched the vial (Figure 3B), which can be used with high efficiency in difficult-to-handle samples [14]. Figure 2 The photograph of Sphingomonas sp. XLDN2-5. A is the SEM image of Sphingomonas

sp. XLDN2-5 (magnification × 15,000). B is the TEM image of microbial cell/Fe3O4 biocomposite (magnification × 36,000). Figure 3 Digital photo of microbial cell/Fe 3 O 4 biocomposite suspension before (A) and after collection (B) using a magnetic field. Biodegradation activity and reusability of microbial cell/Fe3O4 biocomposites With the purpose of understanding the biodegradation activity of the microbial cell/Fe3O4 biocomposite, the biodegradation rates of free cells and microbial cell/Fe3O4 biocomposite were tested at 30°C, respectively. Figure 4A showed that the microbial cell/Fe3O4 biocomposites had the same biodegradation activity as free Sphingomonas sp. XLDN2-5 cells. These results indicated that the Fe3O4 nanoparticle coating did not have a negative effect on the biodegradation activity of Sphingomonas sp. XLDN2-5.