バクテリアセルロース研究の現状と課題

Abstract

An outline of the current study and the future work of bacterial cellulose is hereunder described. The study regarding the said material is summarized to the three types of researches. The first is the research concerning the explanation of the biosynthetic mechanism of the cellulose. The second is the research to make ascertain the structure formation mechanism of the bacterial cellulose. Thirdly, the effective utilization of the bacterial cellulose has been examined.With relation to the first subject, it is explained that cellulose is synthesized with the reaction of UDPG and the synthetase existing upon the cell membrane of Acetobacter xylinum. The cellulose -synthetase is activated when bis- (3'→ 5') cyclic diguanylic acid is taken in, and it has been made ascertained that cellulose synthesis will be possible. However it is not yet explained how the structure of the cellulose-synthetase is and what the reactional structure of UDPG is like.With reference to the second theme, the following is ensured : A cellulose chain is extruded in a noncrystalline state from cells and crystallization is in progress in accordance with the time variation. Finally, a microfibril comprised of cellulose I crystals with a 40 Å diameter is formed. Themicrofibril thus obtained is formed with cellulose chains pushed forward from a rosette existing upon the cell membrane. Moreover with the nascent cellulose in a noncrystalline state, there exists a precursory structure to form the cellulose I crystals. With regard to the precursory structure, there is difference in views at present.In connection with the thied problem, investigation for various kinds of application and development is vigorously being promoted. For example, application for separation membranes, acoustic diaphragms, various types of medical pads, artificial skins, high-strength and high-elasticity composite materials, food processing materials, etc. are available. Among the above, acoustic diaphragms have already been put to practical use.