The major component of the plant cell wall – cellulose – and the major component of the crustaceans’ exoskeleton – chitin – are the two most abundant polysaccharides in nature. They comprise a huge reserve of organic carbon, making use of which would provide a green alternative for the oil based production of fuels and commodity products. For instance, by fermenting the glucose from the degradation process of cellulose, the second generation bioethanol can be produced, which can be used as a motor fuel. Also the residues from many industries like agriculture, forestry, and fishery are rich in cellulose and chitin. Thus the use of these would help decreasing the amount of wastes and better use of biomass. More efficient use of raw materials is inevitable in the light of growing need for energy and raw materials by mankind. The usage of cellulose and chitin as a raw material for industry is challenged by their recalcitrance towards both, chemical and enzymatic degradation, which is caused by their crystalline structure. Enzymes are protein molecules produced by living organisms for accelerating chemical reactions. In nature cellulose and chitin are degraded by microorganisms, who produce variety of different enzymes – celluloses and chitinases – for that purpose. Unfortunately the enzymatic degradation of cellulose and chitin is relatively slow. This decreases the cost efficiency of biomass based products and makes it difficult to compete with oil based products. The positive thing is that like all the biotechnological applications, enzymatic degradation of cellulose and chitin has a high potential for improvement. Although the enzymes are complex molecules, scientists are able to change their structure and properties. For doing so it is necessary to know exactly how the enzymes work, which reaction conditions and enzymes’ properties favor and which disfavor their performance.
Our project concentrates on dissecting the mechanism of cellulases and chitinases on the molecular level. We ask, which properties of the enzymes are important and can they be made better? We focus especially on the enzyme property called processivity. Processivity describes enzymes´ ability to degrade long polysaccharide chains without dissociation. Our cooperation relies on the prolonged experience of Dr. Väljamäe’s group from the University of Tartu on cellulase research including state of the art research methods on one hand and the prolonged experience of Dr. Sørlie’s group from the Norwegian University of Life Sciences on chitinase research including the unique collection of chitinase variants on the other hand. Due to the similarity of the molecular structures of cellulose and chitin the lessons learned with one can be used with the other and vice versa. We hope that our united efforts take us one step closer to understanding the mechanism of cellulose and chitin degradation and thus to the better use of different waste products containing them.