Biobleachování

Biobleachování, also known as biological bleaching or bio-lignin removal, is an environmentally friendly process used primarily in the pulp and paper industry to delignify wood pulp. It utilizes microorganisms, typically fungi and bacteria, to break down lignin, a complex polymer that binds cellulose fibers in wood. This process reduces the need for harsh chemical bleaching agents, such as chlorine compounds, which can generate harmful byproducts.

The most common biobleachování methods employ lignin-degrading enzymes produced by white-rot fungi, such as Phanerochaete chrysosporium. These enzymes, including laccases, manganese peroxidases, and lignin peroxidases, selectively attack the lignin structure, making it more soluble and easier to remove. The pulp is incubated with the selected microorganisms or their enzymes under controlled conditions, typically in a bioreactor.

Biobleachování offers several advantages. It significantly reduces the discharge of toxic effluents associated with conventional bleaching, leading to a cleaner environment. It can also lead to cost savings by decreasing the consumption of chemicals and energy. Furthermore, the process can preserve the strength of cellulose fibers better than some chemical methods, potentially resulting in higher quality paper. However, challenges remain, including optimizing the efficiency of microbial degradation, controlling process parameters, and the time required for effective delignification. Research continues to improve the speed and effectiveness of biobleachování for broader industrial application.