title: Formation of highly twisted ribbons in a carboxymethylcellulase gene-disrupted strain of a cellulose-producing bacterium.
abstract: Cellulases are enzymes that normally digest cellulose; however, some are known to play essential roles in cellulose biosynthesis. Although some endogenous cellulases of plants and cellulose-producing bacteria are reportedly involved in cellulose production, their functions in cellulose production are unknown. In this study, we demonstrated that disruption of the cellulase (carboxymethylcellulase) gene causes irregular packing of de novo-synthesized fibrils in Gluconacetobacter xylinus, a cellulose-producing bacterium. Cellulose production was remarkably reduced and small amounts of particulate material were accumulated in the culture of a cmcax-disrupted G. xylinus strain (F2-2). The particulate material was shown to contain cellulose by both solid-state (13)C nuclear magnetic resonance analysis and Fourier transform infrared spectroscopy analysis. Electron microscopy revealed that the cellulose fibrils produced by the F2-2 cells were highly twisted compared with those produced by control cells. This hypertwisting of the fibrils may reduce cellulose synthesis in the F2-2 strains.
authors.affiliation: Graduate School of Life Science, University of Hyogo, Hyogo, Japan. nakait@sci.u-hyogo.ac.jp
authors.forename: Tomonori
authors.initials: T
authors.lastname: Nakai
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sugano
authors.forename: Makoto
authors.initials: M
authors.lastname: Shoda
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sakakibara
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Oiwa
authors.forename: Satoru
authors.initials: S
authors.lastname: Tuzi
authors.forename: Tomoya
authors.initials: T
authors.lastname: Imai
authors.forename: Junji
authors.initials: J
authors.lastname: Sugiyama
authors.forename: Miyuki
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yamauchi
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Mineyuki
mesh_terms: D002236:Carbohydrate Conformation; D050260:Carbohydrate Metabolism; D002480:Cellulase / Q000235:genetics* / Q000378:metabolism*; D002482:Cellulose / Q000096:biosynthesis* / Q000737:chemistry*; D041822:Gluconacetobacter xylinus / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D019906:Nuclear Magnetic Resonance, Biomolecular; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D002482:Cellulose; D002480:Cellulase; C019826:carboxymethylcellulase