Beiträge zur Struktur der Bakteriencellulose

Franz, Erich; Schiebold, E.

doi:10.1002/prac.19430010104

Cited by 5 publications

(5 citation statements)

References 12 publications

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“…By optical microscopy, Franz and Schiebold determined that small regions of non-stretched cellulose membranes were arranged with preferred orientations, whereas stretched membranes exhibited an overall axiality (Franz and Schiebold 1943). However, neither uniplanar nor uniaxial orientations are typically homogeneously uniform across sample planes.…”

Section: Directionalitiesmentioning

confidence: 99%

“…This is enabled by the fact that as-produced BC is characterized by structural hierarchy common to cellulosic materials (Paajanen et al 2019): On the molecular level, it is semicrystalline (Hermans and Weidinger 1948). On the supramolecular levels, primary aggregates with diameters of 2 nm (Ross et al 1991;Iguchi et al 2000) form fibrils with widths of ≈ 100 nm (Franz and Schiebold 1943;Iguchi et al 2000), which in turn self-assemble into ribbons or bands (Haigler et al 1982), in a complex multistep process in the extracellular space (Ross et al 1991).…”

Section: Introductionmentioning

confidence: 99%

“…It solid-phase density in the wet state is typically ≈ 0.01 g ⋅ cm −3 , and most commonly expressed as its ability to hold about 1 g of water per centigram of cellulose (Pandit and Kumar 2021;Campano et al 2016). The orientation of cellulose fibrils in a BC pellicle was described by Franz and Schiebold (originally in German) as a "tangled, jumbled network of strands" (Franz and Schiebold 1943). Nevertheless, they observed regions with uniform path differences under crossed Nicols, indicating that locally, fibrils may be aligned parallel.…”

Section: Introductionmentioning

confidence: 99%

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Structural and mechanical anisotropy in rheotactically aligned bacterial cellulose

Gmach

Opdenbosch

2022

Cellulose

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In this work, we demonstrate the preparation of oriented bacterial cellulose from Komagataeibacter sucrofermentans by rheotactic growth in a simple and adaptable setup. The resulting materials were assessed by their yields, geometric densities, and by X-ray diffraction, scanning electron and optical microscopy, and mechanical testing. They exhibited large differences in toughness, resulting from differences in fracture strain or highly anisotropic strengths. Their growth characteristics, structural and mechanical anisotropies and crystalline phase characteristics are discussed and compared to statically grown references and to instances from the literature. Here, we consider the length scales of structural anisotropy in native bacterial cellulose pellicles, and the origin of mechanical anisotropy. Further, we identify a tentative limit on achievable structural alignment in bacterial cellulose, as well as a correlation between crystallinity and disorder in the crystalline phase of bacterial cellulose.

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Section: Directionalitiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Structural and mechanical anisotropy in rheotactically aligned bacterial cellulose

Gmach

Opdenbosch

2022

Cellulose

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“…Wie bereits erwahnt, ergeben diese jungen Membranen kein Elektroneninterferenz-Diagramm. Erst 57 Tage nach der Inokulation gelang as Franz und Schiebold (1943), an Hand von Rontgen-und Elektronendiagrammen eine Art Ringfasertextur nachzuweisen, obschon die Faden nach zwei Tagen gut sichtbar sind (Figur 11 und 12).…”

Section: Elektronenoptisde Aufnaliinen Con Bakteriencelluloseunclassified

Elektronenoptische untersuchungen über den feinbau von gelen

Mühlethaler

1948

Makromol. Chem.

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1. Vanadinpentoxyd‐Gel An Hand der elektronenoptischen Aufnahmen können wir uns ein anschauliches Bild vom Aufbau retikular disperser Kolloide machen. Es zeigt sich, daß die Gele durch ein zusammenhängendes Micellargerüst charakterisiert sind, dessen Maschen offen miteinander kommunizieren. Die Verzweigungen und Verschmelzungen auseinanderweichender und zusammenlaufender Stränge sind deutlich sichtbar. 2. Schleim Im Epidermisschleim der Quittensamen werden feine Stränge von ca. 100 Ä Dicke nachgewiesen. Aus Analogie zu andern Samenschleimen, die Cellulosefäden von mikroskopischen Dimensionen enthalten (z. B. Cobaea scandens) darf geschlossen werden, daß diese Stränge die chemisch nachgewiesene Cellulose des Quittenschleims vorstellen. 3. Bakteriencellulose Mit Hilfe Cellulose aufbauender Bakterien konnte gezeigt werden, daß frisch gebildete Cellulose nicht sogleich in kristallisierter Form auftritt. Bei B. xylinoides erscheint sie zuerst in Form eines im El.‐Mikr. strukturlosen Häutchens auf der Oberfläche der Kulturflüssigkeit. Dieser Film ist jedoch nicht stabil, sondern beginnt in dünnste Fäden auszukristallisieren. 4. Cellulosefasern Es wird über eine neue, von Heuberger (Eidg. Materialprüfungsanstalt St. Gallen) entwickelte Methodik zur schonenden Zerfaserung von Cellulosefasern mittels Ultraschallwellen berichtet. Die longitudinalen Schwingungen, die durch einen geeigneten Schallgeber in einer Flüssigkeit erzeugt werden, spalten die Faser ohne irgendwelche Querbrüche in allerfeinste Stränge bis 60 Å Dicke auf, die mit den Micellarsträngen von Frey‐Wyßling identifiziert werden.

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“…The original electron microphotographs of Franz and Schiebold 1 showed that the bacterial membranes consist of a thick network of fibers and ribbons. They concluded that the ribbons had a thickness of about 100A and a breadth about 5oooA, and that they were composed of smaller fibers (microfibrils) about 200A in diameter.…”

mentioning

confidence: 99%

Biosynthesis of Cellulose by Acetobacter Xylinum. II. Morphological Observations on the Formation of Cellulose Microfibrils by Acetobacter Xylinum

Takai

Watanabe

1975

Polym J

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Electron-microscopic observations of an early stage of a logarithmic phase of bacterial cellulose formation show ill-defined and branched fibrillar elements extending from an amorphous substance of cell envelope. This may be interpreted as the initial crystallization of a cellulosic high polymer. In the photographs of cell cross sections, it has been observed that rather slightly staining rod-like materials about 30-40A in breadth and ca. 1000A in length are in the cytoplasm of some cells. Composite fibrils become predominant at a middle stage of a logarithmic growth phase. They were in the form of threads having a constant breadth of ca. 500A with sharply defined boundaries, and consisting of a few microfibrils. The separate fibrils have intertwined to form tangled masses, and built tough membranes which could not be torn easily. Lysozyme treatment of the microfibril has demonstrated that the shape is a fiat ribbon with a constant breadth and a thickness of ca. 50-100A. This treatment has the effect of hydrolytic degradation across the axial direction of the microfibril. In addition, a pronounced swelling of the microfibril occurs anisotropically perpendicular to the axis of the microfibril. A bacterial cellulose membrane negatively stained with sodium phosphotungstate, showed a longitudinal periodicity with a ca. 200A interval. KEY WORDS Incubation I Bacterial Cellulose 1 Fibrillar Element I Cell Envelope I Cross Section I Rod-like Material I Composite Fibril 1 Microfibril I Tangled Mass I Membrane I Lysozyme Treatment 1 Negative Staining Periodicity 1

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Beiträge zur Struktur der Bakteriencellulose

Cited by 5 publications

References 12 publications

Structural and mechanical anisotropy in rheotactically aligned bacterial cellulose

Structural and mechanical anisotropy in rheotactically aligned bacterial cellulose

Elektronenoptische untersuchungen über den feinbau von gelen

Biosynthesis of Cellulose by Acetobacter Xylinum. II. Morphological Observations on the Formation of Cellulose Microfibrils by Acetobacter Xylinum

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