Concomitant production of xylanases and cellulases from Trichoderma longibrachiatum MDU-6 selected for the deinking of paper waste

Sixty fungal cultures were isolated from agricultural soil, industrial soil, forest canopy soil having decomposed leaf litter and compost samples collected from different regions of India. Fifteen fungal cultures were selected qualitatively for the production of xylanase and cellulases and were identified employing ITS, NS and MNS primers. The enzyme cocktail consisting of 3811 IU g(-1) of xylanase and 9.9 IU g(-1) of cellulase from Trichoderma longibrachiatum MDU-6 was selected quantitatively for the deinking of diverse paper wastes. The enzyme production increased two fold when produced at tray level in comparison with flasks. The enzyme cocktail was effective in the deinking of old newspaper samples with significant removal of chromophores, phenolics and hydrophobic compounds and less sugar loss. While in case of examination papers and laser printed papers, ink removal was not very significant. Moreover, the sugar loss was significantly high in case of examination papers. The deinking results were further confirmed with FTIR analysis. Deinked newspaper pulp sample shows brightness of 52%, which was 9.6% high than its control sample. The ERIC value for deinked newspaper pulp was found to be 655.9 ppm. Thereafter, the deinked newspaper pulp was examined under light microscope after differential staining with safranin and malachite green and also examined under scanning and transmission electron microscope, which revealed fibrillation and perforation.