Efficacy of Manganese Peroxidase Produced from Maize in Pulp Bleaching

The pulp and paper industry require the removal or bleaching of lignin as an important manufacturing step for many of their products. Chemical bleaching is the preferred current process for whitening because of its relatively low cost. The bleaching process uses large amounts of chlorinated and caustic chemicals to brighten raw pulp which is brown in color due to the presence of residual lignin. Depending on the bleaching chemicals used, the liquid waste stream may contain a number of toxic chemicals which may eventually accumulate in rivers and oceans. Additionally, wastes from bleaching tanks may emit hazardous air pollutants. Consequently, large amounts of chlorinated organic byproducts such as dioxin are generated. The successful completion of this project would provide an enzymatic alternative to chemical bleaching. This process would have a positive impact on the environment by eliminating many of the unwanted caustic products released. The key to the successful adoption of an enzymatic process will be to develop a system of production for the enzyme that can compete favorably in function and cost. Early work has suggested that transgenic plants may be able to provide such as system and the work proposed here is focused on demonstrating this in a practical manner.