AU-PE89 Xylanase for Improved Bleaching of Paper Pulps

Xylan is a major component of wood and non-wood fibres. During cooking of pulps, the xylan is partially dissolved, modified and re-precipitate onto the fibre surface. The application of the enzyme, xylanase, to the cooked pulp removes some of the re-precipitated xylan. This opens up the pulp matrix, allowing the release of trapped soluble lignin. At the same time it allows bleaching chemicals to penetrate more effectively. The overall result is improved bleachability of the pulp with resulting reduction in usage of bleaching chemicals. AU-PE89 Xylanase is an enzyme that degrades xylan. AU-PE89 is specific for xylan and does not degrade cellulose. Xylanases produced by different microorganisms operate optimally over a range of pH and temperature. AU-PE89 was developed from a proprietary strain of bacterium for the paper pulp industry. AU-PE89 is particularly suited to the elevated temperatures and alkaline pH of kraft pulps. The manufacturing process involves growing a specific proprietary bacterium in bioreactors (fermenters), separating the cells from the broth, and concentrating the clarified liquid. The product is prepared as a concentrated liquid or light brown powder.