Bacterium xylinum

In 1886, Brown11 discovered an organism which formed extremely tough membranes when cultivated m suitable nutrient solutions containing carbohydrates such as D-fructose, D-mannitol or D-glucose ethanol, sucrose or starch did not support membrane formation by this organism which Brown called Bacterium xylinum ) (Acetobacter xylinum). The membranes were readily soluble in cuprammonium hydroxide solution and yielded a dextrorotatory sugar upon acid hydrolysis. These properties and the results of combustion analysis led him to believe that the membrane was cellulose. 

In 1886 Brown described the properties of two organisms. Bacterium aceti and Bacterium xylinum. He had isolated them from the surface of a... 

Synonyms Acetobacter xylinus (Brown 1886) Yamada 1984 Gluconace-tobacter xylinus (Brown 1886) Yamada, Hoshino and Ishikawa 1998 Bacterium xylinum Brown 1886. 

Mixed cultures of a broad variety of microorganisms, especially of bacteria and yeasts in particular have been used for millenia to produce dairy products, bread, and alcoholic beverages. The foundations for a scientific approach, however, were laid by L. Pasteur [1] in 1862 by using a pme culture of Bacterium xylinum to transform [2] ethanol into acetic acid. In 1874, Dumas [3] reported the reduction of sulfur to hydrogen sulfide by fermenting yeast, Sacdiaromyces ceremsiae. The first reduction ("phytochemical reduction") of an organic molecule imder anaerobic conditions was performed by Windisch [4] in 1898, and fiufuryl alcohol 2 was obtained from furfural 1 (Figure 21.1). 

The identification of terminal complexes in the Gram-negative bacterium Acetobacter xylinum now appears to be in doubt. Previously, a single linear row of particles observed on the outer lipopolysaccharide membrane... 

The gram negative bacterium Acetobacter xylinum produces a ribbon of crystalline cellulose I whose neutral sugar content is 96.8% glucose and 3.2% xylose (1). Growth of A. xylinum in a medium containing... 

L-Iditol (sorbi6rite), the last of the four naturally occurring hexitols, occurs in service berries along with sorbitol. After removing sorbitol from the juice by fermentation to L-sorbose with the sorbose bacterium, Acetobacter xylinum, the n-iditol is crystallized as a benzylidene derivative. It has been prepared by the action of sodium amalgam on... 

In the past few years, some impressive observations have been made by microscopists studying cells actively engaged in cellulose synthesis. It is now generally accepted by most workers that, in the bacterium A. xylinum, in most algae, and in all of the higher plants, cellulose is synthesized at the cell surface by an enzyme system localized in the plasma membrane. The notable exception to this conclusion concerns those algae which synthesize a cell wall composed of cellulosic scales such scales are synthesized intracellularly by way of the Golgi apparatus (see Ref. 57 and references cited therein). 

L-Allulose (LXI) was prepared by Steiger and Reichstein through the oxidative fermentation of allitol (LX) by the sorbose bacterium, Acetobacter xylinum. The product was isolated and purified by means of its crystalline diacetone derivative, of m. p. 57° and - -99 in... 

The formation of crystalline microfibrils has been elucidated using the bacterium Acefol acter xylinum as cellulose producing model. It appears that individual cellulose chains are extruded at multiple cellulose-synthesizing sites located in the cytoplasmatic membrane of the organism. Cellulose synthesis produces 12 to 16 cellulose chains into the surrounding medium... 

In 1973 the structure (157) or (158) was proposed for a C35 hopane derivative, bacteriohopanetetrol, from the bacterium Acetobacter xylinum. Structure (157) is attractive as a precursor for the extended hopane derivatives obtained from geological sources (see Vol. 3, p. 228 and Vol. 5, p. 145). Rohmer and Ourisson have now confirmed"" the validity of (157) and have shown the presence of both (22R)- and (225)-epimers. Periodate cleavage of the tetrol followed by sodium borohydride reduction and acetylation afforded the epimeric acetates (159) identical with synthetic samples prepared from diploptene (160). A range of Acetobacter species and... 

Although cellulose is the most abundant polysaccharide in plants, attempts to elucidate the mechanism of its biosynthesis have proved to be surprisingly difficult. However, considerable progress has been achieved with the cellulose-forming bacterium Acetobacter xylinum. 

L-Allulose (LXI) was prepared by Steiger and Reichstein through the oxidative fermentation of allitol (LX) by the sorbose bacterium, Acetobacter xylinum. The product was isolated and purified by means of its crystalline diacetone derivative, of m. p. 57° and [a]o +99° in acetone. To the latter compound was assigned the l,2 3,4-diisopropyl-idene-L-allulofuranose structure LXII because it could be oxidized by alkaline permanganate to a crystalline uronic acid (LXIII) which, from its behavior, must have the carboxyl group in the 6- and not the 1-position. After removal of the isopropylidene groups from LXII, the free sugar, L-allulose (LXI), was obtained as a colorless sirup with — 3.3° in water. It is not fermented by yeast. 

---