Roles for microbial enzymes in pulp and paper processing

Microbial enzymes are enabling new technologies for processing pulps and fibers. Xylanases reduce the amount of chemicals required for bleaching; cellulases smooth fibers, enhance drainage, and promote ink removal; lipases reduce pitch; laccases and lignin-degrading enzymes reduce color in effluents, and promote lignin removal. In the future, these and other enzyme-based processes could lead to much cleaner and more efficient pulp and paper processing. Enzymes may also be used to enhance fiber bonding and modify fiber structures. More than 50 million metric tons of paper are produced in North America every year. Globally, paper and paper board production exceeds 270 million metric tons. If even a fraction of this total is enzymatically processed, it could mean a great expansion of the existing enzyme industry. From a fundamental perspective, cellulases, xylanases, and lignin-degrading enzymes are increasingly well understood at a molecular level, and the diversity of these enzyme families is expanding rapidly with the identification of new organisms and direct cloning. Enzyme based analyses and molecular modeling are improving our understanding of the pulp matrix. Novel process developments include the use of co-mediators and the integration of enzymes into commercial environments. This paper will provide an introduction to the symposium andmore » an overview of the field.« less