|Biely, Peter - SLOVAK ACADEMY|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: February 4, 2005
Publication Date: June 1, 2005
Citation: Biely, P., Cote, G.L. 2005. Microbial hemicellulolytic carbohydrate esterases. In: C.T. Hou, editors. Handbook of Industrial Biocatalysis. Chapter 21. Taylor & Francis. p. 21-24. Technical Abstract: In this chapter, we introduce and discuss the biocatalytic potential of microbial carbohydrate esterases. These esterases operate on highly hydrated substrates, such as partially acylated polysaccharides occurring in plant cell walls. This is a special group of carboxylic acid esterases discovered relatively recently and, therefore, less well-known than lipases and other esterases, particularly in view of their biocatalytic potential. Microbial hemicellulolytic systems involved in degradation of naturally occurring hemicelluloses include three types of esterases: 1. Acetylxylan esterases, which deacetylate partially acetylated 4-O-methylglucuronoxylan, the major hardwood hemicellulose; 2. cinnamoyl esterases, feruloyl esterases, and related aryl esterases, which liberate phenolic acids and their dimers from plant cell walls, where they mainly occur as esters with L-arabinofuranose-containing polysaccharides, such as L-arabino-D-xylans and L-arabinans; 3. acetylgalactoglucomannan esterases, which deacetylate O-acetyl galactoglucomannans, the major softwood hemicellulose. In comparison with lipases and some plant esterases that have been used for decades as powerful tools for hydroxyl group protection and deprotection in carbohydrate chemistry, the catalytic properties of hemicellulolytic esterases are relatively unknown beyond their biological functions in plant cell wall degradation and, therefore, remain underutilized as practical biocatalysts.