Mannans properties

In the linear konjac mannan, the degree of acetylation profoundly affects the solubility and flow properties of this hydrocolloid. The acetyl substitution prevents self-association of the mannan chains, but following deacetylation chain interactions become more energetically favorable [230]. 

These properties of the enzyme are good for the production of D-mannose from P-mannan in the presence of the P-mannanase described above. 

Future research. From an industrial standpoint, the major requirements of p-mannanases are thermostability and the ability to hydrolyse crystalline and/or amorphous mannan to low DP oligosaccharides. Enzymes with such properties could find application in such processes as coffee extraction and in enzymic treatment of wood pulp. 

Christensen et al. [93] successfully obtained a divalent cluster having -600-1500 enhanced binding properties. We have also demonstrated that dendritic mannosides such as 66 (Scheme 11) can provide up to 100-fold higher affinity (on a per-mannoside basis) when used to inhibit the binding of plant lectins (Concanavalin A and pea lectins) to yeast mannan [85]. As these interactions are at the origin of host infections by fimbriated bacteria, mannoside dendrimers can form the basis of novel antiadhesin molecules. 

Considering the close resemblance in general structure and food-reserve function of these polysaccharides, a certain similarity in properties might be expected, and this similarity will be discussed in later Sections. Also, the parent polysaccharides cellulose, mannan, and esparto xylan are all intrinsically water-insoluble the progressive introduction of the monosaccharide and disaccharide stubs, if... 

The linear, but highly branched, molecular structure of the galactomannans is the reason for some specific properties which are quite different from those of the unbranched cellulose-like and water-insoluble mannans and glucomannans. Galactomannans are hydrated in cold water and give stable solutions even in acidic formulas. The interactions of galactomannans with other polysaccharides are the base of a variety of industrial applications. 

The properties of the enzymes used in this study have been described in former publications (10,11,15). Important for the following interpretation are their hydrolytic specificities. The xylanase did not hydrolyze either isolated mannans or celluloses—or only to a very small extent (10). The same is true for the mannanase with respect to xylans and celluloses (11,15). The avicelases, which were not purified to the same extent as the xylanase and mannanase, did not hydrolyze mannans, but they degraded xylans besides crystalline cellulose (10). Also, the highly purified cellobiohydrolase C (12) degraded xylan to some extent (Dr. E. K. Gum, Jr., personal communication). 

Hess and coworkers53 have isolated mannose-containing polysaccharides from both ivory nuts and from pine wood pulp, and these mannans appeared to have identical properties. Both gave specific rotations of approximately —45° in N sodium hydroxide and +285° in cuprammonium (0.04 mole hexose anhydride, 0.10 mole copper, 10.0 moles ammonia per liter). The exact composition of these polysaccharides is not known Yundt54 has recently stated that mannan A from ivory nuts assayed only 50 percent mannose. The cuprammonium rotation data cannot be interpreted in terms of the fine structure until the composition of the mannans is known with certainty. 

The second class comprises conventional solids, defined by a chemical formula, but whose property requirements are very minimal. In this class we included lignin, cellulose, mannan, galactan, xylan, arabinan and the biomass. The properties specified in the database include molecular weight, heat of formation, solid molar volume, and solid heat capacity. 

A. A. Kolender, C. A. Pujol, E. B. Damonte, M. C. Matulewicz, and A. S. Cerezo, The system of sulfated alpha-(l—>3)-linked D-mannans from the red seaweed Nothogenia fastigiata Structures, antiherpetic and anticoagulant properties, Carbohydr. Res., 304 (1997) 53-60. 

The main structural constituents of Saccharomyces cerevisiae yeast cell wall are glucans and mannans with a minor proportion of chitin (Walker 1998). Manno-proteins are located in the outer layer of the yeast cell wall and determine most of the surface properties of the wall. Vasserot et al. (1997) studied the capacity of yeast lees to adsorb anthocyanins in an attempt to reduce the detrimental effects of charcoal on the color of red musts and wines. Experiments based on model wine solutions revealed that yeast lees possess a greater affinity for anthocyanins than... 

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