Study On Immobilization And Characteristics Of Aeromonos Sp. F3Onto The Nano-Super Ferrofluid

Nano-super ferrofluid refers to the magnetic metal or magnetic oxide superfine powder and has the magnetic response property of polymer microsphere with magnetic separation, guide, mark and fixed functions. It combines the magnetic inorganic particles and organic polymer formed to the certain magnetism and the special structure of the composite microspheres. The ferrofluid is widly used in the medicine industry, agriculture, textile, chemical and biomedical engineering, and this technology have been developed for several decades. Especially, more attention are given in separation engineering. The nano-super ferrofluid applied in biological separation technology need to show perfect physical and chemical characteristic,and small size, specific surface area and larger adsorption capacity. The ferrofluid with small size, physical and chemical stability properties never shown more influence on the substrate and product;The cell are easily separated from its broth under magnetic field.(1) In this paper, the carboxyl-functioned nano-super ferrofluid were prepared with coprecipitation method by KMnO4, and the best preparation conditions are optimized. The X-ray diffraction (XRD), diffraction particle size analyzers (LPSA) and FTIR were used to characterize the properties of the nano-super ferrofluid. The results shown that the diameter of the ferrofluid was about180nm, indicated the diameter distribution of functioned were more uniform. The ferrofluid have more functional groups on its surface.(2) The nano-super ferrofluid was directly adsorped to the cell surface of Aeromonos sp.F3and the cells were separated under the magnetic field. It can be used in the cells separation for reutilization of cell. The immobilization conditions such as cell/particle ratio, pH, temperature were investigated. The optimum condition was that the cells were immobilized onto the nano-super ferrofluid for0.5h at30℃with the cell/particle ratio of3.1and the pH8. The immobilized cells were used to recultured for seven times by separation under the magnetic field and replacing fresh fermentation culture. The result shown that its relative enzyme activity reached at60%.The research indicated that the immobilized cells cav be used to produce the bio-acvtivity material have the stable enzyme activity. So the ferrofluid can be used to immobilize microbial cells and separate of cell for production of the bio-acvtivity material.