There is huge amounts of waste sludges produced in pulp and paper industry that imposes significat environmental and economical problem. The purpose of the following work was to show that paper sludge can be used as a substrate for fungi producing lignocellulolytic enzymes. Twenty-nine fungal strains were tested for their ability to grow on paper sludge. Ten different strains (H35, CHP 4, PP3, PLO 4, HYUL, POLY xy, AASC, COCO, GAL 5 in PLO ZABR) that exhibited highest growth-rate on paper sludge were chosen for further analysis. Enzymatic activities in enzyme extracts from selected fungal cultures were measured and three strains were chosen for further experiments. We inoculateted autoclaved (124 °C, 99 min), heat treated (60°C, 180 min) and thermally untreated paper sludge with strains H35, PP3 and HYUL. No growth of any of the strains was observed on paper sludge pretreated by exposure to 60 °C for 180 min. Among the strains able to grow on non-pretreated and autoclaved substrate, best performance was observed with the strain HYUL. Paper sludge overgrown by HYUL was homogenized and crude enzyme extract was analyzed for endoglucanase, xylanase and laccase activities. Number and molecular weights of the lignocellulolytic enzymes in the extracts were estimated on zymograms. During growth on paper sludge, strain HYUL produced at least 7 different cellulolytic enzymes (20-100 kDa), 6 xylanolytic enzymes (5-22 kDa) and 1 enzyme with laccase activity (10 kDa).
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