INDUSTRIAL APPLICATION OF ALKALINE CELLULASE ENZYMES IN PULP AND PAPER RECYCLING: A REVIEW

"Industrial utilization of waste paper in the production of a new one is increasing globally. Currently, the pulp and paper industry is one of the largest consumers of wood. Based on the demand, due to global economic growth, an increasing number of trees are harvested each year, also leading to increased amounts of wastes and pollutants, which represent a serious hazard for the environment. Chemical agents, such as sodium hydroxide, hydrogen peroxide, sodium carbonate, diethylenetriaminepentacetic acid, sodium silicate and surfactants, are used in large quantities by paper industries as part of the conventional methods of deinking waste paper, leading to the need to apply expensive wastewater treatments in order to meet environmental regulations. On the other hand, enzymes, such as cellulase, lipase, xylanase, pectinase, hemicellulase, amylase and esterase, can substitute conventional chemical methods of deinking waste papers. These enzymes have been reported to be environmentally friendly, as compared to the chemicals involved in conventional methods. Several decades ago, it was established that microbial enzymes might be useful in the processing of paper, since it is composed of natural polymers, such as cellulose, hemicelluloses and lignin. However, despite their enormous potential, the industrial use of these enzymes is still limited, being affected by lack of microbial strains capable of generating a high amount of alkaline cellulase. This paper provides an insight into recent research performed with the objectives of optimizing alkaline cellulase enzymes production and applying them in pulp and paper processes."