Enhanced biodegradation of di-n-butyl phthalate by Acinetobacter species strain LMB-5 coated with magnetic nanoparticles

Phthalate acid esters (PAEs) are widely present in a variety of consumer products and they pose a public health concern due to the high mobility and hazards. In this study, we designed an immobilized method to eliminate phthalates by using Fe3O4@NH2 nanoparticles (NPs). The surface-modified NPs showed a good dispersion property, and the particle size was approximately 230 nm. The results showed that Acinetobacter sp. strain LMB-5 could be coated by the prepared magnetic particles allowing easy separation from solution by applying an external magnetic field. The coated cells possessed adaptability to a wide range of pH and high tolerance towards toxic substances. More importantly, when the temperature was elevated to 60 °C, the coated cells also exhibited remarkable degradability. There was no change in the main metabolites during the biodegradation between the free cells and immobilized ones through GC/MS analysis to detect the degradation intermediates. These results show that immobilization method using magnetic nanoparticles is a promising way for degradation of phthalates in application.