THE NON-SPHERULITIC BIREFRINGENCE IN CELLULOSE PELLICLES OF ACETOBACTER XYLINUM

1966 ◽  
Vol 12 (5) ◽  
pp. 909-913 ◽  
Author(s):  
J. Ross Colvin
Keyword(s):  
Bacterial Cellulose ◽  
Acetobacter Xylinum ◽  
Common Origin ◽  
Cellulose Microfibrils ◽  
Parallel Orientation

The development of non-spherulitic, threadlike birefringence, observable in pellicles of bacterial cellulose from Acetobacter xylinum, is described. This birefringence is a consequence of the formation of bundles of parallel cellulose microfibrils within the pellicle. The reason for this parallel orientation is unknown and all attempts to influence it have failed. The development of the birefringent threads within the pellicle is often accompanied by formation of streaks of lipid-like material Boating on the surface of the medium. The distribution of these streaks is similar to the distribution of the non-spherulitic birefringence. This similarity in distribution may be a reflection of a common origin.

The structure of spherulites of bacterial cellulose from Acetobacter xylinum

1974 ◽  
Vol 20 (4) ◽  
pp. 509-512 ◽  
Author(s):  
L. C. Sowden ◽  
J. Ross Colvin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Bacterial Cellulose ◽  
Acetobacter Xylinum ◽  
Cellulose Microfibrils ◽  
Polarizing Microscopy ◽  
Scanning Electron

Evidence from phase and polarizing microscopy as well as scanning electron microscopy indicates that the cellulose microfibrils in the spherulites of bacterial cellulose are oriented tangentially, not radially. Also, the orientation may be limited to only a fraction of the thickness of the pellicle. It is suggested that the tangential deposition may be caused by a gradient of concentration of a weakly soluble inhibitor of cellulose formation about a center.

THE FORMATION OF SPHERULITES IN PELLICLES OF BACTERIAL CELLULOSE

1965 ◽  
Vol 11 (4) ◽  
pp. 641-643 ◽  
Author(s):  
J. Ross Colvin
Keyword(s):  
Bacterial Cellulose ◽  
Higher Plants ◽  
Synthetic Polymers ◽  
Acetobacter Xylinum ◽  
Cellulose Microfibrils ◽  
Two Dimensional ◽  
Radial Orientation ◽  
Great Complexity ◽  
Dendritic Structures

Two-dimensional analogues of spherulites are formed in the pellicle of bacterial cellulose produced by static cultures of Acetobacter xylinum. These spherulites are much larger (sometimes more than 1 cm diameter) than those usually observed in other natural or synthetic polymers. They are due to the radial orientation of bacterial cellulose microfibrils in limited regions of the plane of the pellicle. These spherulites interact to form characteristic, dendritic structures of great complexity which resemble leaves of higher plants.

THE INDUCTION OF BIREFRINGENCE IN PELLICLES OF BACTERIAL CELLULOSE FROM ACETOBACTER XYLINUM BY LIPIDS

1967 ◽  
Vol 13 (7) ◽  
pp. 837-844 ◽  
Author(s):  
J. H. Carson ◽  
L. C. Sowden ◽  
J. R. Colvin
Keyword(s):  
Bacterial Cellulose ◽  
Bacterial Culture ◽  
Acetobacter Xylinum ◽  
Cellulose Microfibrils

Some lipids, particularly diglycerides, cholesterol, or cholesterol derivatives, are able to induce visible birefringence in pellicles of extracellular bacterial cellulose produced by Acetobacter xylinum when they are added in small amounts to the surface of cultures. This birefringence is due to orientation of a fraction of the cellulose microfibrils, not the cells, in the pellicle. Orientation may begin with small microscopic domains which are present in pellicles of untreated cultures and some of which may overgrow others under the influence of a lipid. How the lipids induce alignment of the microfibrils in the bacterial culture is unknown but the process appears to involve an interaction between newly formed extracellular microfibrils and the microcrystalline surface of the lipid.

Extension of bundles of cellulose microfibrils on agar surfaces by Acetobacter xylinum

1968 ◽  
Vol 14 (2) ◽  
pp. 93-95 ◽  
Author(s):  
E. J. Gibson ◽  
J. Ross Colvin
Keyword(s):  
Electron Microscope ◽  
Bacterial Cellulose ◽  
Growth Pattern ◽  
Acetobacter Xylinum ◽  
Cellulose Microfibrils ◽  
Agar Surface

The extension of bundles of bacterial cellulose microfibrils on agar surfaces was investigated using pseudoreplicas in the electron microscope. Two classes of bundles were distinguishable; those which were composed of many short individual microfibrils of nearly uniform length (1–3 μ) and those in which there were only a few long microfibrils (> 50 μ). The growth pattern of single straight cellulose microfibrils, the proportion of bundles containing many short microfibrils and the extent of coiling of microfibrils were influenced strongly by the sample of agar used to form the surface. These observations are consistent with the suggestion that the mode of extension of bacterial cellulose microfibrils is sensitive to the concentration of an extracellular precursor in small pools on the agar surface.

What are the ranges and basis of auxeticity in the phases of cellulose microfibrils?

2017 ◽  
Author(s):  
Akwasi Asamoah
Keyword(s):  
Bacterial Cellulose ◽  
Raman Spectra ◽  
Laser Power ◽  
Microfibrillated Cellulose ◽  
Glass Slide ◽  
Flax Fibre ◽  
Cellulose Microfibrils

<p>One sample of 1D bundle of cellulose microfibrils in the form of lignified flax fibre (0.10526 mm x 10 mm), and one 2D networks of cellulose microfibrils in the form of tunicate cellulose (0.07 mm x 5 mm x 10 mm), bacterial cellulose (0.135 mm x 5 mm x 10 mm) and microfibrillated cellulose (0.08 mm x 5 mm x 10 mm) were put on a glass slide parallel to the principal spectrometer axis. Raman spectra were measured all round in-plane under both half (in 5° steps) polarisation from 0° to 360° in extended mode between 100 cm<sup>-1</sup> and 1150 cm<sup>-1</sup> in 3 accumulations at 10s exposure and 100% laser power. The cursor was placed at the peak of the 1095 cm<sup>-1</sup> band, and intensity read.</p>

The growth of cellulose microfibrils from Acetobacter xylinum

1957 ◽  
Vol 23 ◽  
pp. 652-653 ◽  
Author(s):  
J.R. Colvin ◽  
S.T. Bayley ◽  
M. Beer
Keyword(s):  
Acetobacter Xylinum ◽  
Cellulose Microfibrils

scholarly journals Bacterial Cellulose as a Substrate for Microbial Cell Culture

2014 ◽  
Vol 80 (6) ◽  
pp. 1926-1932 ◽  
Author(s):  
Na Yin ◽  
Thiago M. A. Santos ◽  
George K. Auer ◽  
John A. Crooks ◽  
Piercen M. Oliver ◽  
...  
Keyword(s):  
Cell Culture ◽  
Cell Growth ◽  
Physicochemical Properties ◽  
Stationary Phase ◽  
Bacterial Cellulose ◽  
Growth Rates ◽  
Bacterial Cell ◽  
Acetobacter Xylinum ◽  
Primary Factor ◽  
Nutrient Diffusion

ABSTRACTBacterial cellulose (BC) has a range of structural and physicochemical properties that make it a particularly useful material for the culture of bacteria. We studied the growth of 14 genera of bacteria on BC substrates produced byAcetobacter xylinumand compared the results to growth on the commercially available biopolymers agar, gellan, and xanthan. We demonstrate that BC produces rates of bacterial cell growth that typically exceed those on the commercial biopolymers and yields cultures with higher titers of cells at stationary phase. The morphology of the cells did not change during growth on BC. The rates of nutrient diffusion in BC being higher than those in other biopolymers is likely a primary factor that leads to higher growth rates. Collectively, our results suggest that the use of BC may open new avenues in microbiology by facilitating bacterial cell culture and isolation.

Biosynthesis of Carboxymethylated Bacterial Cellulose Composite for Wound Dressing

2011 ◽  
Vol 685 ◽  
pp. 322-326 ◽  
Author(s):  
Jun Wei Yu ◽  
Xiao Li Liu ◽  
Chang Sheng Liu ◽  
Dong Ping Sun
Keyword(s):  
Bacterial Cellulose ◽  
Wound Dressing ◽  
Culture Medium ◽  
Acetobacter Xylinum ◽  
Water Holding Capacity ◽  
Water Soluble ◽  
Transmission Rates ◽  
Measurement Results ◽  
Water Holding ◽  
Cellulose Composite

A novel bacterial cellulose (BC) composite (carboxymethylated-bacterial cellulose, CM-BC) was synthesized by Acetobacter xylinum by adding water-soluble carboxymethylated cellulose (CMC) in the culture medium. FTIR results showed that CM-BC is obtained by the incorporation of CMC in the network of BC. Water-holding capacity and water vapor transmission rates (WVTR) of CM-BC and BC are determined. The WVTR of CM-BC is comparable to that of BC, but the water-holding capacity of CM-BC is improved compared with BC. Tensile strengths measurement results showed that the fracture stress of CM-BC is higher than that of BC, indicating that CM-BC have more potential wound dressing applications than BC.

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