838-844The study examines the ability of
white-rot fungus Phanerochaet chrysosporium NRRL 6361 to deink the
wastepapers under investigation; namely, newsprint, writing, and printing
papers. The wastepapers are inoculated with culture of P. chrysosporium
NRRL 6361 under sterilized conditions at different pHs (5-11.4) in the
presence and absence of growth media. The optimization of the process parameters
shows that the incubation for one week at 32 ± 2°C results in maximum deinking
of recycled newsprint at pH 11.4 with brigtness 39 per cent and maximum brightness
of recycled printing papers 75 per cent at pH 7.2, while for writing paper the
maximum brightness obtained is 80 per cent at pH 7.5. The α-cellulose content
of recycled wastepapers is found to increases,
while lignin decreases during deinking by P. chrysosporium NRRL 6361. The
results indicate that the fungus do not have any affect on the cellulose. Scanning
electron microscope (SEM) is used to follow the fungus growth hyphae through
the wastepapers after one week of incubation. The mechanical properties of the handsheets
made from recycled wastepapers slightly decrease. Therefore, starch-silicate
complex is used to overcome the decrease of the mechanical properties