초록
<P>Cellulolytic enzyme production by newly isolated Aspergillus niger HN-1 was statistically optimized using Plackett–Burman and central composite design (CCD). Optimum concentrations of 2, 0.40, 0.01, and 0.60 g L <SUP>–1</SUP> for KH<SUB>2</SUB>PO<SUB>4</SUB>, urea, trace elements solution, and CaCl<SUB>2</SUB>·2H<SUB>2</SUB>O, respectively, were suggested by Design-Expert software. The two-stage optimization process led to a 3- and 2-fold increases in the filter paper cellulase (FP) and β-glucosidase activities, respectively. FP, β-glucosidase, endoglucanase, exopolygalaturonase, cellobiohydrolase, xylanase, α-<SMALL>l</SMALL>-arabinofuranosidase, β-xylosidase, and xylan esterase activities of 36.7 ± 1.54 FPU gds<SUP>–1</SUP>, 252.3 ± 7.4 IU gds<SUP>–1</SUP>, 416.3 ± 22.8 IU gds<SUP>–1</SUP>, 111.2 ± 5.4 IU gds<SUP>–1</SUP>, 8.9 ± 0.50 IU gds<SUP>–1</SUP>, 2593.5 ± 78.9 IU gds<SUP>–1</SUP>, 79.4 ± 4.3 IU gds<SUP>–1</SUP>, 180.8 ± 9.3 IU gds<SUP>–1</SUP>, and 288.7 ± 11.8 IU gds<SUP>–1</SUP>, respectively, were obtained through solid-state fermentation during the validation studies. Hydrolysis of alkali-treated rice straw with crude cellulases resulted in about 84% glucan to glucose, 89% xylan to xylose, and 91% arabinan to arabinose conversions, indicating potential for biomass hydrolysis by the crude cellulase consortium obtained in this study.</P><P><B>Graphic Abstract</B><BR><IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jafcau/2013/jafcau.2013.61.issue-51/jf403083g/production/images/medium/jf-2013-03083g_0006.gif'></P>