Cellulases hydrolysis

Cellulase Hydrolysis of 3-l,4-glucan bonds in such polysaccharides as cellulose, yielding p-dextrins. 

Paulo, A. C., and Almeida, L. (1994], Cellulase hydrolysis of cotton cellulose The effects of mechanical action, enzyme concentration and dyed substrates, 10, 353-360. 

There is a clear need for a specific labelling method for carbohydrates on heterogenous fibres. Antibodies can be used as specific markers for carbohydrates. Oligosaccharides derived from xylan by acid hydrolysis (10) and from xyloglucan by cellulase hydrolysis (//) have been used as antigens for production of polyclonal antibodies. Polymeric carbohydrates have also been used as antigens for antibody production (12-14). 

Cellulase and all chemicals used in this work were obtained from Sigma. Hydrolysis experiments were conducted by adding a fixed amount of 2 x 2 mm oflSce paper to flasks containing cellulase in 0.05 M acetate buffer (pH = 4.8). The flasks were placed in an incubator-shaker maintained at 50 °C and 100 rpm. A Box-Behnken design was used to assess the influence of four factors on the extent of sugar production. The four factors examined were (i) reaction time (h), (ii) enzyme to paper mass ratio (%), (iii) amount of surfactant added (Tween 80, g/L), and (iv) paper pretreatment condition (phosphoric add concentration, g/L), as shown in Table 1. Each factor is coded according to the equation... 

Cellulase enzyme complexes consist of three major types of proteins that synergistically catalyze the breakdown of a cellulosic substrate. Because the enzymes are strictly substrate-specific in their action, any change in the structure or accessibility of the substrate can have a considerable influence on the course of the hydrolysis reaction. A pretreatment method based on exposing cellulosic substrate to phosphoric acid solution [9] and addition of the nonionic... 

Figure 4. Content of galacturonic acid in the soiuble fraction after hydrolysis of AIS with polygalacturonases [a], with polygalacturonases and pectin methylesterase [b], with pectinases and cellulases [c].

The cambium was isolated firom spruce (Picea abies) logs felled in October-November. The bark was stripped off, and the cambium was removed by gentle scraping. The isolated cambium was immediately fiozen in liquid nitrogen and fi-eeze-dried. The carbohydrate composition of the isolated cambium was analysed by HPLC after enzymatic hydrolysis using Pectinex Ultra and a mixture of cellulases and hemicellulases (Buchert et al 1993). 

Recovery of cellulases from wheat-straw hydrolysis fermentation broth [83]... 

Water removal on the paper machine has been shown to improve as a result of limited hydrolysis of the fibres in recycled paper. Mixtures of cellulases and hemicellulases were found to decrease the SR-value, which describes the drainage behaviour of the fibres (45), The effect is apparently due to fibrillation or change in the composition of fine particles. 

The anaerobic biological conversion of the major polymeric components of MSW identified require appropriate microorganisms and hydrolytic enzyme systems. Extracellular hydrolytic enzymes, such as cellulases and lipases, have been shown to be effective in the post hydrolysis of anaerobic digester efQuent solids 34) or pretreatment of complex organic polymers before the digestion process 48),... 

Both digester systems exhibit extremely low levels of detectable cellulase activities (exoglucanase, endoglucanase, and -glucosidase) when compared to industrial saccharifying processes (See Table III) in which the hydrolysis of cellulose in the feedstock is optimized with respect to enzyme loading. Therefore, the data indicate the level of improvement that may be made to attain maximum rates for cellulose hydrolysis in the anaerobic reactor system. 

Hydrolysis of delignified wheat straw up to 90% was obtained in 96 hours with the cellulase system produced in SSF with wheat straw. It took only 72 hours to obtain over 90% hydrolysis of wheat straw with cellulase system produced with SSF on Pro-cell (Table VII). It is interesting to note that the quantity of cellobiose in the hydrolysate obtained with the cellulase system produced on Pro-cell was higher than that of the cellulase system produced on wheat straw. This is consistent with the observation that cellulase system produced on Pro-cell had a lower ratio of FP cellulase )3-glucosidase (1 0.77) as compared to that produced on wheat straw (1 1.2). However, this cellulase system had a faster hydrolysis rate it took only 72 hours to obtain over 90% hydrolysis. This might be related to cotton hydrolyzing activity of this cellulase system (Table V). 

Table VIL Comparison of Hydrolysis of Delignified Wheat Straw with Cellulase Systems of Trichoderma reesei QMY-1 Produced Under Solid-State Fermentation ...

Hydrolysis with 20 lU FP cellulase/g washed steam-exploded wood (10% cone) in 48 hr. 

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