Combinatorial enzyme approach for conversion of agricultural fibers to functional products

Plant cell wall polysaccharides consist of polymeric backbones decorated with various types of substitutions.  For example, xylan contains a β-1,4-linked xylopyranosyl chain decorated with at least six types of side groups.  Likewise, xyloglucans, pectins and others consist of varieties of side chain substitutions that can be targeted by specific enzymes.  The presence of these side groups as well as their positions, density, and types of linkages influence the pattern of enzymatic degradation of the main chain polymer, and determine the structural outcome of the oligosaccharide fragments produced.  The use of enzymes to surgically remove the side group moieties individually, sequentially, and in combinatorial design can alter the degradation pattern of the modified main chain.  This would result in products of numerous oligosaccharides, with structural diversity that would translate into different and unique reactivity and functional properties.  The diverse population is to be screened in high-throughput schemes for candidates possessing the target biological and/or functional properties.  This novel enzyme technology using the concept of combinatorial chemistry should be applicable for exploration of new structures and functions in all aspects of biopolymer degradation.  Preliminary results illustrate the application of this technology as a new approach in bioconversion research.