A fungus that calls mangrove forests home produces enzymes that can degrade lignin, a complex compound that helps give plants their structural strength and resiliency. This tough chemical compound is also difficult to degrade which poses a problem for the paper industry since lignin is a major contributor to the brown color of unbleached pulp. Strong oxidizing agents, particularly chlorine bleach, have traditionally been used to break down lignin to produce white paper, but this process generates toxic chlorinated compounds as waste products. Fungal enzymes not only break down lignin without generating toxic byproducts, they do not attack cellulose fibers needed to produce strong paper products.Edit Summary
"Extracellular degradative enzymes such as cellulases, xylanases and ligninases of several terrestrial fungi have found biotechnological applications in paper and pulp industries. In the production of paper, residual lignin from wood pulp is chemically liberated by using chlorine bleaching...forming chlorinated lignin derivates such as chlorolignols. These are toxic, carcinogenic and recalcitrant to degradation. Biobleaching is an important alternative to reduce the use of chlorine. This is carried out using ligninolytic enzymes manganese peroxidase and laccase or by using hemicellulolytic enzyme xylanase. Microbial xylanases that are thermostable, active at alkaline pH and cellulase-free are generally preferred for biobleaching of paper pulp...A marine-derived fungus NIOCC #3 [Aspergillus niger] isolated from mangrove detritus produced xylanase that was thermostable at 55°C, cellulase-free, and active at pH 8.5 and was found to be effective in biobleaching...resulting in a reduction of 30% chlorine consumption during bleaching." (Raghukumar 2008:25).