Immobilization of enzymes and antibodies on magnetic particles isolated from magnetotactic bacteria

点击翻译按钮获取中文摘要

We have developed the novel use of magnetic particles isolated from magnetotactic bacteria. Magnetotactic bacteria were incubated at 25゜C for a fwe weeks in the sludge enriched with 0.005% sodium succinate and 0.005% sodium nitrate, and collected by use of a magnetic harvesting apparatus. Magnetotactic bacteria were mainly cocci and rod type. These bacteria contained about 10 to 20 magnetic particles. Biogenic magnetic particles were separated form magnetotactic bacteria by digestion with NaOH. The magnetic particles were 500-1000<ang> in size and aminly consist of magnetite (Fe_3O_4), which analysed by an energy dispersive X-ray analyzer and a highresolution transmission electron microscope. This particles were coverd with organic thin films.Immobilization of enzymes and antibodies on biogenic magnetic particles were carried out by treating magnetic particles with <gamma>-(aminopropyl)triethoxysilane and glutaraldehyde, and incubated with antibodies and enzymes at 4゜C for 12hr. Large … More amounts of enzymes and antibodies were immobilized on biogenic magnetic particles because of its uniform sharp and small size. Enzymes immobilized on magnetic particles show high activity.We measured glucose concentration by using glucose oxidase immobilized on magnetic particles and optic fiber sensor. Glucose concentration could be measured linearly in the range of 0.1-4.0 mg/ml. Enzyme reaction was enhanced by magnetic stirring. Selective separation of E.coli was also done by use of anti-E.coli antibody immobilized on magnetic particles. After magnetically stirring and separation, E.coli cell concentration decreased. Whereas the cell concentrations of L.acidphillus and S.cervisiae didn't decreased after magnetic separation. Therefore, particular cell could be separated selectivity. Furthermore, the small amount of antigen could be detected rapidly by microspopic observation of antigen-antibody reaction forming agglutination by use of the antibodies immobilized on magnetic particles. Biogenic magnetic particles are promising for the future application in clinical field. Less