4.3 Degradation and modification of cellulose acetates by biological systems |
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Authors: | Juergen Puls Clemens Altaner Bodo Saake |
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Affiliation: | Institute of Wood Chemistry and Chemical Technology of Wood, Federal Research Centre of Forestry and Forest Products, D-21001 Hamburg, Germany |
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Abstract: | A survey is given on recent findings in the enzymology of cellulose acetate degradation. Acetyl esterases have been identified as the principal enzymes, initiating cellulose acetate degradation as a prerequisite for endoglucanase-catalyzed cellulose acetate depolymerisation. Acetyl esterases are provided by nature to deacetylate naturally occurring partly acetylated polysaccharides, i.e. xylan and chitin. Accordingly they are not designed to attack high DS cellulose acetate. Under these circumstances acetyl esterases require a pretreatment of cellulose acetate, leading to some reduction in DS, in case highly substituted material should be degraded. One of these treatments is composting under the conditions of which a partial deacetylation may occur under the action of heat and high pH, facilitating the accessibility for acetyl esterases. However from the present knowledge it cannot be excluded that certain microbial specialists exist, being capable to degrade high DS cellulose acetate. |
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Keywords: | acetyl esterase endoglucanase carbohydrate esterase family NMR-spectroscopy deacetylation composting degree of substitution |
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