Cellulose, composition digestion

Figures 1 and 2 show positive correlation, although of varying degrees of goodness of fit, between the specific activities of endo ucanase, exoglucanase, and -glucosidase activities with the cellulose composition and degradation in digester feed, respectively. These data indicate a direct relationship between the cellulose content in the feed and cellulase enzyme complex production by the digester consortia. In this system, as in many others studied, cellulose is an effective inducer of cellulase secretion (67,68),...

SBAS reinforcing fibers were fabricated via the ACI s viscous suspension spinning process (VSSP) °. In this process, cellulose is digested in a sodium hydroxide aqueous solution in the form of a viscous liquid (viscose) that is mixed with the SBAS powder dispersed in a water slurry (Figure 2a). It should be noted that the lower amount of HTE, compared to the matrix composition, was used in the mixture for fibers to increase their sintering temperature and prevent strong fiber-to-matrix bonding. 

Climatic conditions, age, and the digestion process influence not only the structure of fibers but also the chemical composition. Mean values of components of plant fibers are shown in Table 4. With the exception of cotton, the components of natural fibers are cellulose, hemi-cellu-lose, lignin, pectin, waxes, and water-soluble substances. 

These two columns, DEAE-cellulose at neutral pH followed by DEAE-Sephadex at pH 2.7, suffice to separate all the components with different nucleotide compositions present in complete pancreatic ribonuclease digests of RNA molecules with at least about 10 nucleotides before digestion. Sometimes, these fractions contain only... 

Dried and never-dried pulps have the same lignin, hemicellulose, and cellulose content at the same yield, but very different digestibilities. The composition of a pulp is therefore a poor guide to its digestibility, some other factor obviously being of considerable importance, and, if this is true of the present series of samples, it is likely to be true also of forages of different species or maturity. 

Additional experiments are needed to relate not only the monosaccharide composition of the fibers fed to fecal output but also the structures of those fibers and how they may have been modified In the digestive tract even If not fermented. The effect of fiber particle size and pretreatment should be studied. Free sugar, starch, cellulose and uronlc acid measurements should be made in order to obtain a more complete picture of what survives and what is metabolized. The effect of dietary fibers on the digestion and utilization of other polysaccharides and other food components should be studied. This Information, together with fermentation data. Including gas and VFA production, will provide a better understanding of the role and value of different dietary fibers and their effects on nutrient bloavallablllty. 

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