Figure 3

Specific activity towards para -nitrophenyl (pNP) substrates from supernatants from A. niger cultured with either wheat straw or willow. A ‘*’ symbol is used to indicate whether the differences between willow and straw cultures were statistically significant (Student’s t-test, p < 0.05). Abbreviations are: pNP-β-cel: 4-Nitrophenyl-β-D-cellobioside; pNP-α-ara: 4-Nitrophenyl-α-L-arabinofuranoside; pNP-β-glu; 4-Nitrophenyl-β-D-glucopyranoside and pNP-β-xyl: 4-Nitrophenyl-β-D-xylopyranoside. The error bars represent standard errors.