Figure 4. Comparison of extracellular (a, b) and intracellular (c, d) cellulolytic enzyme specific activities attained by Aspergillus niger biofilm (BF) and submerged (SF) cultures at 0% (a_w = 0.976) and 20% (a_w = 0.942) ethylene glycol. The error bars on the graphs represent two replicate samples.