Screening, structure-function relationship analysis, and improvement of useful carbohydrate-related enzymes


For the development of industrial enzymes, we are working on the screening, analysis, and improvement of a novel enzyme. In order to explore the new enzyme, we are using not only classical microbial screening, but also metagenomic screening that can utilize genetic resources in the environment directly. We perform a detailed analysis of the enzymes to reveal the structure-function relationship, and the enzymes are then improved by rational design based on structural information and the directed evolution technique. Presently, our main targets are carbohydrate-related enzymes:

  1. An enzyme for saccharification of cellulosic biomass: We are studying enzymes for cellulosic biomass degradation. Cellulose, the main component of the plant cell wall, is composed of glucose. Cellulases degrade cellulose to produce glucose, which can be used in bio-ethanol production and bio-refinery. Currently, cellulase formulation derived from the filamentous fungal genus, Trichoderma, is used widely; however, it does not possess sufficient activity. Therefore, we are now developing an enzyme to compensate for the weakness of the Trichoderma cellulase formulation.
  2. Enzymes which degrade hemicellulose, ‘hemicellulases’ Hemicelluloses are polysaccharide components of the plant cell wall, and are structurally diverse. Hemicellulases, which degrade hemicelluloses, also display various activities in order to respond to a variety of hemicellulose structures. We are conducting research on unique enzymes that specifically recognize the structure of hemicelluloses. Enzymes that strictly recognize these sugar chain structures are useful research tools for the production of various oligosaccharide structures (which may prove useful as novel bio-based materials or as physiologically active substances), and for structural analysis of hemicellulose. Sugar chain structure-specific enzymes may prove useful as a research tool, likely in combination with restriction enzymes, for molecular biology. Several enzymes developed by us have been used as tools for the structural analysis of hemicelluloses and oligosaccharide production.