EXPLORATION AND ANALYSIS OF A LIGNOCELLULASE CONSORTIUM FOR DEINKING OF RECYCLED PAPER IN THE ECO-PAPER INDUSTRY.

Deinking is the process of removing and separating ink from printed paper fiber. Large quantities of chemicals are used in the traditional deinking process in the paper industry. This is not only expensive, but the use of chemicals in large quantities also leads to many environmental problems. To reduce the chemical usage, one eco-solution is to use enzymes as deinking agents. In this article, an enzymatic newspaper deinking using a lignocellulase cocktail consisting of a cellulase from Actinobacillus sp. and recombinant xylanase from Geobacillus thermoleovorans IT-08 expressed in Escherichia coli DH5α (namely pTP-510) is reported. In order to increase the brightness of the deinked paper, a laccase from the wild type fungus Aspergillus sp. was added to the enzyme cocktail. The ratio of cellulase to xylanase in the cocktail was 4:1 and the laccase activity was varied. To assess the deinked paper quality, its brightness, strength, and surface profile were analyzed. The results showed that the addition of laccase 0.291 U to the enzyme cocktail leads to a brightness level of 60.4 % (ISO 2470), which exceeds the SNI 14-0091-1998 standard of 55 % (ISO 2470). The condition for tensile index was 25.36 Nm/g (ISO 1924/2), which is greater than the SNI 14-0091-1998 standard of 21.5 Nm/g (ISO 1924/2). Moreover, scanning electron microscopy (SEM) revealed that the surface of the enzymatically deinked paper is more tenuous than the control. [ABSTRACT FROM AUTHOR]