Medium used for cellulase production contained (g/L): NaNO3, 3; MgSO4.7HO, 0.5; KHPO4, 1; KC1, 0.5 and supplemented with 1 mL FeSO5.7H2O as trace element. The medium was adjusted to pH 5.5 and inoculated aseptically by adding Aspergillus terreus spore suspension (approximately 2x107 spores/mL) to 50 mL of sterilized medium containing 5% (w/v) sugarcane bagasse in a 250 mL Erlenmeyer flask and incubated at 35C for 24 h at 200 rpm. Table 1 shows the results obtained for media optimization before proceeding to statistical optimization. Table 1: Effect of different bagasse and yeast extract concentrations on cellulase enzyme activity of Aspergillus terreus Concentration Bagasse (%) 1 2 3 4 5 6 Yeast extract (g L-) 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 Endoglucanase activity (U mL-) 0.32 0.47 0.65 0.88 0.96 0.73 1.40 1.90 2.47 1.99 1.67 1.51 1.35 1.18 074 Protein content (mg mL-) 0.90 1.83 2.50 3.16 3.30 1.88 2.17 1.82 2.04 2.70 2.68 3.10 3.76 3.20 2.52 Specific activity (U mg- protein) 0.35 0.25 0.26 0.28 0.29 0.39 0.65 1.04 1.21 0.74 0.63 0.48 0.35 0.37 0.29 Explain the medium used is either synthetic or complex medium for fermentation production.