PRODUCTION OF CELLULASE BY A WILD STRAIN OF CHAETOMIUM-GLOBOSUM USINGDELIGNIFIED OIL PALM EMPTY-FRUIT-BUNCH FIBER AS SUBSTRATE

Studies on the feasibility of using delignified oil palm empty-fruit-b unch (OPEFB) fibres as a substrate for cellulase production by Chaetom ium globosum strain 414 were carried out in shake-flask cultures conta ining different types and concentrations of nitrogen source. Peptone, as nitrogen source, gave maximum production of all the three main comp onents of the cellulase complex (endoglucanase or carboxymethylcellula se, cellobiohydrolase or filter-paper-hydrolysing enzyme and beta-gluc osidase), followed by yeast extract, urea, KNO3 and (NH4)(2)SO4. The m aximum specific growth rate (mu(max)) of C. globosum strain 414 grown in medium containing OPEFB and peptone was 0.038 h(-1). In all the fer mentations, the fungus was able to produce all the three cellulases wi th significant amounts of beta-glucosidase, except when using (NH4)(2) SO4 as nitrogen source, where beta-glucosidase was not produced. With 6 g/l peptone and 10 g/l delignified OPEFB fibres, the fungus produced maximum concentrations of FPase, carboxymethylcellulase and beta-gluc osidase: 1.4, 30.8 and 9.8 U/ml, giving productivities of 10, 214 and 24 U l(-1) h(-1), respectively. The cellulase mixture, partially purif ied by ammonium sulphate precipitation, was able to hydrolyse delignif ied OPEFB fibres, converting about 68% of the cellulosics to reducing sugars after 5 days.