الفهرس | Only 14 pages are availabe for public view |
Abstract Biomechanical pulping is an experimental process that uses a fungal treatment of lignocellulosic materials as an alternative to chemicals prior to mechanical pulping. The potential benefits of biomechanical pulping included saving energy during mechanical pulping, improving sheet strength properties, and reducing undesirable waste effluents. In view of that, the present study was designed to study the effects of pretreating bagasse with most efficient delignifying strains, prior to thermomechanical pulping. A number of 13 actinomycetes isolates, 9 fungal isolates (isolated from soil), and 6 white-rot fungi strains were tested for biodegradation of bagasse and rice straw. Only two white-rot fungi were selected as high efficient strains. In a series of experiments, recommended the optimum conditions for the highest lignin degradation, which were 50 or 100 ml of modified MV medium containing 0.005 % glucose, 0.05 % yeast extract, 0.21 % ammonium sulfate, and 0.5 % pretreated bagasse at 121 °C / 20 min., inoculation with 10 % standard inoculum of Ceriporiopsis subvermispora CZ-3 or Phanerochaete chrysosporium ME-446 (10 ml contains 0.15 g dry weight) and incubation at 30 or 37 °C, respectively for 8 weeks. Electron microscopy studies were carried out on the bio-treatment of bagasse. |