Cellulose decomposers

Under the condition chosen cellulose decomposes much faster than lignin. Adding nitrogen accelerates the decomposition of holocellulose as well as... 

Condensed-Phase Mechanisms. The mode of action of phosphorus-based flame retardants in cellulnsic sy stems is probably best understood. Cellulose decomposes by a noncalalyzed route lo tarry depolymerization products, notably levoglucosan, which then decomposes to volatile combustible fragments such as alcohols, aldehydes, ketones, and hydrocarbons. However, when catalyzed by acids, the decomposition of cellulose proceeds primarily as an endothermic dehydration of the carbohydrate to water vapor and char. Phosphoric acid is particularly efficaceous in this catalytic role because of its low volatility (see Phosphoric Acids and Phosphales). Also, when strongly heated, phosphoric acid yields polyphosphoric acid which is even more effective in catalyzing the cellulose dehydration reaction. The flame-retardanl action is believed to proceed by way of initial phosphory lation of the cellulose. 

N03 -N (Yamanaka 1995b). Cellulose-decomposing bacteria decrease after the treatment and remain in much smaller numbers for a considerable period (He and Suzuki 2004). 

Methyl alcohol is the simplest member of the alcohols and is also known as methyl alcohol or wood alcohol. It was originally produced from the distillation of wood at high temperature in the absence of air, hence it is known as wood alcohol or wood spirit. While heating, wood which is composed of cellulose, decomposes into simpler compounds. Some of these compounds are acetone, acetic acid and methyl alcohol. The mixture obtained is passed through cold water to condense it. 

Wood flour and sawdust do not melt but rather decompose above 190°C. This is, again, due to a more susceptible to temperature lignin and hemicellulosics, and because pure cellulose decomposes above 240°C. 

For the last few years, we have investigated the cellulase components of Pseudomonas fluorescens var. cellulosa in special regard to the physiological relation of their synthesis and localization to the cultural conditions. This pseudomonad is an aerobic mesophilic cellulose-decomposing bacterium isolated earlier by Ueda et al. (39) from field soil. Some of the enzymatic properties of cellulases obtained from it have previously been reported (28). In the present review, the results of our recent studies (42) are described and discussed together with the related works of other authors. [In these studies, activities of cellulase and aryl / -glucosidase were assayed by the same methods as described in a recent paper (31), and that of amylase by the blue value method modified by Fuwa (10)]. 

There is some slight evidence that Clostridia can fix nitrogen when growing in association with aerobic cellulose decomposers but such an association would not be expected, except possibly where there are anaerobic pockets in an otherwise aerobic soil, or where alterations of aerobic and anaerobic conditions occur. Such fixation in soils is probably negligible. 

Only a few solvents are known to dissolve cellulose completely, and solid cellulose decomposes before melting. Therefore, it is difficult to study the mesophase behavior of cellulose. Chanzy et al. [32] reported lyotropic mesophases of cellulose in a mixture of jV-methyl-morpholine-Af-oxide and water (20-50%), but were unable to determine the nature of the mesophase. Lyotropic cholesteric mesophase formation in highly concentrated mixtures of cellulose in trifluoroa-cetic acid + chlorinated-alkane solvent [33] and in ammonia/ammonium thiocyanate solutions [34] has been studied, and although poor textures were obtained in the polarizing microscope, high optical rotatory power has been measured in an optical rotation (ORD) experiment, which could be fitted to the de Vries equation [Eq. (3)] for selective reflection beyond the visible wavelength region and was taken as proof of a lyotropic chiral nematic phase. 

Equation (40) shows that cellulose hydrogenation is first order with respect to cellulose concentration. The reactor pressure increases as the cellulose reacts, to signify that the pressure in the reactor, P is proportional to the concentration of cellulose decomposed. 

Cellulose is a partially crystalline polysaccharide and is the chief constituent of plant fiber. Cotton is the purest natural form of cellulose, containing 90 percent cellulose. Cellulose decomposes before melting and therefore cannot be melt processed. It is insoluble in organics and water and can only be dissolved in strong basic solutions. Regenerated cellulose, also known as rayon, is cellulose that has been precipitated form a basic solution. Cellulose is used in bandages and sutures. Cuprophan is cellulose precipitated fix>m copper hydroxide solutions to form hemo alysis membranes. 

Coughlan, M. R, Mayer, F. (1991). The cellulose-decomposing bacteria and their enzymes systems. In A. Balows, H. G. Truper, M. Dworkin, W. Harder, K. H. Schleifer (Eds.), The prokaryotes (pp. 460-516). Berhn Springer. 

Cellulosic fibres, such as cotton, are the most susceptible to microbial attack and most uses of microbicides are directed at protecting cotton fabrics. Problem causers are cellulose-decomposing fungi and bacteria. Synthetic fibres in general do not as readily biodeteriorate as cellulosic fibres, but staining by microbes may occur without loss of strength. Protection of fabrics with microbicides is also needed to keep textile materials in a hygienic condition. 

E.A. Bayer, Y. Shoham, and R. Lamed, Cellulose-decomposing bacteria and their enzyme systems, in S. Falkow, E. Rosenberg, K.-H. Schleifer, and E. Stackebrandt, eds. The Prokaryotes, Springer New York, pp. 578-617,2006. 

MBT in comparison to the corresponding N-hydroxymethyl derivative (3.4.12.) which is a formaldehyde releasing substance. As a fungicide MBT is especially toxic to superficial moulds and cellulose-decomposing fungi. The antibacterial activity of MBT is marked by a lack of efficacy for Pseudomonads. In practical application, mainly as slimicides, MBT sodium salt solutions therefore contain additionally other dithiocarbamates (e.g. 11.10.1., 11.11.1.). Moreover MBT/sodium MBT is characterized by dual utility, as it serves also as a popular corrosion inhibitor for non-ferrous metals. 

Enrichment cultures of cellulose-decomposing bacteria from the digestive tract were fed to pigs, and these appeared after a time to improve digestion of the cellulose. 

A t)rpical example of a polymer which can act as a char sovuce is cellulose, which has a polyhydric structure and is the polymer present in the largest amoimt naturally on earth. On heating, pure cellulose decomposes through two competitive routes. One involves dehydration of the carbohydrate units (dehydrocellulose) and successive condensation of the resulting unsaturated structures, leading to char. The char peld depends on the type of cellulose and on the conditions of pyrolysis it ranges between 6 and 23%. The alternative reaction is depolymerization to laevoglucosan, which is the main volatile... 

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