The Preparation, Characterization And Application Of Functionalized Yeast Cell Containing Calcium Carbonate Supporter

In recent decades, natural and highly efficient biosystems, such as yeast and M13bacteriophage, haveexhibited their potential to fabricate of minerals. The thought of using the biosystems to synthesizeminerals is a really innovation and may open the door to new strategies for the biosynthesis of minerals,because the biosynthesis can avoid many problems in the field of chemical synthesis currently, such asenvironmental impact, energy loss, safety and noncompatibility with biological systems. But up till now, amajority of the material synthesized by the organism was took advantage of the groups outside theorganism. Here our objective is to prepare a functionalized cell by building a mineral scaffold inside cell.More importantly, the functionalized cell might be used as bio-supporters to deliver different types of drugs,or to do a series of reactions for various applications. Consequently, the present work could further extendthe scientific applications of the biosystems in different fields such as medicinal, environmental, chemical,biological, and material sciences.In the selected topic of this essay, the yeast cell is chosen as the biosynthesizer, that is, the object ofmy study. The calcium hydroxide solution and polysaccharide were added to the system,then in the condition above, in the room temperature, we used a simple way to synthesize nanoscalecalcium carbonate particles in the yeast cells. Subsequently, we used many testing methods, such as theconfocal laser scanning microscope(CLSM), flow cytometry(FCM), high resolution transmissionelectron microscopy(HRTEM), energy dispersive spectrometer(EDS) and so on. In addition, thissystem is non-toxic and pollution-free to the organism and the environment. Therefore, the application onthe drug delivery and heavy metal adsorption is discussed to some extent in this essay.Main points of this paper are as follows:(1) The classification, research status home and abroad and existent problems of the biosynthesis.Meanwhile, the research background and the main content of this essay were introduced.(2) The yeast cell was chosen as the biosynthesizer, particular concentration calcium hydroxidesolution was added, and the polysaccharide as the energy source of cells, the functionalized yeast cell wassynthesized. We used many testing methods, such as the scanning electron microscope (SEM), X-ray diffraction(XRD), Fourier Transform infrared spectroscopy (FT-IR), confocal laser scanningmicroscope(CLSM), high resolution transmission electron microscopy(HRTEM),, flowcytometry(FCM), energy dispersive spectrometer(EDS),etc. to detect the functionalized yeast cell.The result indicated that, the calcium carbonate particles got by means of the method above was locatedinside the yeast cell, the particle size of which is4-6nm. When the nanoscale calcium carbonate is put intothe yeast cell, it won’t lead to the cell’s death, but will inhibit some biochemical processes in some ways,such as delay the yeast’s breeding time.(3) The calcuim carbonate acted inside the functionalized cell acted as the scaffold, the experiment onthe drug transportation was conducted, The outcome demonstrated that, the load capacity of thefunctionalized yeast cell is much higher than the pure yeast cell. What’s more, in the medium of differentpH value, the released quantity of the loaded drug increases when the pH value reduced. This phenomenondemonstrate that this system is pH-sensitive, and has particular potential application.(4) Because the substance inside the functionalized cell were all non-toxic and pollution-free to theorganism and the environment, we chosed it as the biosorbent, conducted lots of experiments in the heavymetal adsorption. The result of biosorption indicates that the functionalized yeast cell, which contains thecalcuim carbonate nanoparticals, is better than the pure yeast cell in the biosorption of both largeconcentration and trace amount of metal ions. This indicates that the calcuim carbonate particles inside thefunctionalized cell improve the features of the yeast cells.In this essay, under the room temprature and taking the organism as the biosynthesizer, thefunctionalized yeast cells containing calcium carbonate is synthesized for the first time. The synthesismethod offers a new experience basis for the biosynthesis research, and also provides the importantexperience and guidance for the mechanism of the biosynthesis researh.