Alteration in protein profile of Pseudomonas aeruginosa (PTSOX4) coated with magnetic Fe3O4 nanoparticles

One of the remarkable features of bacterial species is their capacity for rapid growth when the appropriate environmental condition for growth is provided. Some bacteria, during their growth period, encounter stress factors in their natural environments, such as limitation in growth bioavailability, heat shock, heavy metal, etc. One stress factor not studied is the effect of magnetic Fe3O4 nanoparticles on bacterial growth rate. The effect of magnetic Fe3O4 nanoparticles on the protein profiles of genetically engineered bacterial strain Pseudomonas aeruginosa (PTSOX4), a strain with biological desulfurization characteristic, was investigated. The magnetic Fe3O4 nanoparticles were synthesized using co-sedimentation method, and their morphology was observed by scanning electron microscopy (SEM). The topography of magnetic Fe3O4 nanoparticles was detected by X-ray diffraction, and the average nanoparticle size measured was 40 to 50 nm. The bacterial cells were coated with magnetic nanoparticles, and the SEM electrographs of the bacterial cells indicated that the nanoparticles were uniformly coated on the cell surface. Proteins from both uncoated and coated bacterial cells were extracted by sonication and subjected to two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis. Some novel protein bands appeared in the protein profiles of coated bacterial cells; however, some protein bands disappeared. The two-dimensional gel electrophoresis results highlighted the presence of two different polypeptide groups, with molecular weights of 30 to 56 kDa and 56 to 65 kDa.