Horseradish and potato peroxidase biobleaching of mixed office waste paper

Abstract

Mixed office waste (MOW) pulp was biodeinked with crude enzyme extracted from Penicillium citrinum NCIM-1398. Crude enzyme dose was charged having activities of endo β-1,4-glucanase 6I U/g, xylanase 876.19 IU/g, and amylase 26.53 IU/g. The present study aimed to bleach the biodeinked MOW pulp with 3% H2O2 in the presence of a stabilizing agent viz. 0.1% ethylenediaminetetraacetic acid (EDTA) and 0.1% magnesium sulfate (MgSO4), which improved the pulp brightness up to 4.2% and the ERIC value was reduced by 24.1%. The residual H2O2 left in the pulp slurry after bleaching was subjected to peroxidase treatment using enzyme dose 0.017 U/g at 20 °C for 3 h at 200 rpm. Horseradish peroxidase reduced residual H2O2 in the pulp slurry from 0.30 to 0.05 g/L and improved the brightness of pulp to 88.1%, while the ERIC value was reduced by 20.9%. Potato peroxidase reduced residual H2O2 from 0.30 to 0.04 g/L, reduced the ERIC value by 30.9%, and improved the brightness to 89.2%. Peroxidase treatment was not only observed to consume the residual hydrogen peroxide left after the bleaching stage but also may come up as eco-friendly technology to recycle MOW paper as writing printing grade paper.

Evaluation of Interactions of Added Soybean Peroxidase with Other Nutrients Present in Fish Feeds Using an In Vitro Digestive Simulation

“…These enzymes are considered multifunctional due to their ability to catalyze oxidation or polymerization reactions on a variety of substrates in the presence of hydrogen peroxide (H 2 O 2 ) [15,17]. This feature allows PO to be applied in different areas of industrial biotechnology [18][19][20]. Different studies report the application of PO for humic acid inhibition [21], development of molecular markers [22], bleaching in the paper industry [20] and mitigation of contaminants (e.g., mycotoxins) in food and feed matrices [12,[23][24][25][26].…”

“…This feature allows PO to be applied in different areas of industrial biotechnology [18][19][20]. Different studies report the application of PO for humic acid inhibition [21], development of molecular markers [22], bleaching in the paper industry [20] and mitigation of contaminants (e.g., mycotoxins) in food and feed matrices [12,[23][24][25][26].…”