(532e) Biodegradation of Carbazole by Microbial Cells Coated with Magnetite Nanoparticles

Microbes can remove nitrogen from carbazole through a series of enzyme-catalyzed reactions. Microbial cells of Klebsiella sp. LSSE-H2 were coated with magnetic Fe₃O₄ nanoparticles, which were synthesized by a coprecipitation method followed by modification with ammonium oleate. The average size of the magnetic particles was found to be in the range from 10 to 15 nm. Transmission electron microscopy (TEM) cross section analysis of the cells showed further that the Fe₃O₄ nanoparticles were strongly absorbed by the surfaces of the cells and coated the cells. The coated cells had superparamagnetic properties. The coated cells not only had the same activity as free cells but could also be reused. Biodenitrogenation rate was increased with the addition of Tween 80. The activity decreased less than 23%after three recycles.