Figure 5

Enzyme activity studies. A. Comparative enzymatic activity of secreted or anchored cellulases and xylanases either individually or in a cell consortium. The concentration of hypochlorite pretreated wheat straw (dry matter) in the reactions was 40 g/l, and enzymes (either secreted or anchored) were added at 5 nM. Enzymatic activity is defined as mM soluble reducing sugars following a 24-hour reaction period at 37°C and pH 5. Each reaction was performed in triplicate and standard deviations are indicated. B. Kinetics studies of hypochlorite pretreated wheat straw hydrolysis by the secreted enzymatic consortium (squares) versus the designer cellulosome (diamonds) or the anchored enzymatic consortium (triangles). The concentration of hypochlorite pretreated wheat straw (dry matter) in the reactions was 40 g/l, and enzymatic consortium was added at 5 nM. Enzymatic activity is defined as mM soluble reducing sugars following a 3, 6, 24, 48, 72 or 96-hour reaction period at 37°C and pH 5. Each reaction was performed in triplicate and standard deviations are indicated. C. Soluble sugar production in mM as determined by HPLC analysis following digestion of hypochlorite pretreated wheat straw over a 24, 48, 72 or 96-hour incubation period by the designated cell consortium. Glucose, xylose, arabinose and cellotriose were not detected.