The aim of the present study was to investigate a new approach to P-glucosidase production
of an Aspergillus strain using cheap lignocellulosic material i.e. waste paper in
order to substitute glucose, a generally used carbon source, and thereby reduce the
production cost. The enzyme production was performed and optimized for the highest
beta-glucosidase yield in cofermentation with a Trichoderma strain to support the
degradation of cellulose and to provide the non-cellulolytic Aspergillus with water
soluble carbon source. Batch fermentation experiments of Aspergillus niger BKMF 1305
and Trichoderma reesei RUT C30 were carried out in shake flask cultures. The factors
influencing the enzyme production, such as the concentrations of nutrients and carbon
source, the inoculum ratio of the two species, and the delay in A. niger inoculation
were investigated using a 2(3) full factorial design. The results were analyzed with
the response surface
methodology using commercially available software, Statistica for Windows. All three
examined factors were found significant. The highest beta-glucosidase activity of
3.07 IU/mL was obtained after 7 days of incubation, if 3.3% Aspergillus and 6.7% Trichoderma
inoculum were added at the same time to modified Mandels' medium, in which the concentration
of nutrients was doubled compared to normal Mandels' medium and the carbon source
concentration was set to 20 g/L waste paper.