engleski

Production of lignocellulose degrading enzymes on sugar beet pulp by cellulolytic fungi

The production of sustainable liquid fuels such as bioethanol from renewable resources has become a primary worldwide concern. To date, the major problem of biorefinery processes is the high production cost of enzymes used for the degradation of lignocelluloses into fermentable sugars. Here we report the production of lignocellulolytic, hemicellulolytic and pectinolytic enzymes by three fungi using sugar beet pulp as relatively cheap and readily available substrate. The fungi under investigation were the white-rot basidiomycete Trametes multicolor and the plant pathogens Sclerotium rolfsii and Neurospora crassa. In cultivation experiments the activities of extracellular enzymes, namely cellulases, pectinases, xylanases, arabinases, mannanases, manganese peroxidase, laccase and cellobiose dehydrogenase were differently induced and monitored. By optimization of the cultivation conditions highly efficient enzyme preparations were obtained, which have hydrolytic activity towards sugar beet pulp. The highest arabinase (1.3 U mL−1), pectinase (0.78 U mL−1) and carboxymethyl cellulase (0.49 U mL−1) activities were observed in cultures of Sclerotium rolfsii grown on sugar beet pulp. The highest xylanase (0.88 U mL−1), manganese peroxidase (0.3 U mL−1) and laccase activities were detected in Trametes multicolor cultures. Neurospora crassa does not perform equally well as the other two fungi. The clearified culture supernatants were used to degrade sugar beet pulp enzymatically and found to hydrolyze all polymers efficiently and fast.

Manganese peroxidase; Laccase; Cellobiose dehydrogenase; Cellulase; Pectinase; Xylanase; Arabinase; Trametes multicolor; Sclerotium rolfsii; Neurospora crassa; Sugar beet pulp; Bioethanol

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