Enzymatic Hydrolysis of Wheat Straw in a Stirred-Tank Reactor

In an attempt to elucidate the effect of some operating conditions on the rate and extent of enzymatic hydrolysis of lignocellulosic materials in a stirred tank reactor, wheat straw was hydrolyzed by mixing with two pitched-blade impellers mounted on a shaft under various atmospheric conditions: static air in headspace, N₂ gas flowing over the surface of the medium, and minimal static air by a lid touching the surface of the medium. The presence of N₂ gas over the reaction medium produced by the highest 6.9 % (w/w) conversion in 36 hours. The initial conversion when N₂ gas flowed in the headspace (2.9 % w/w), and when a lid was used (2.9 % w/w) as compared to conversion in air presence (2.3 % w/w), seems to indicate that the enzyme activity was affected due to oxidation in the presence of air. The observed low conversion yield was probably the result of the non sterile conditions imposed by industrial requirements for the production of biofuel ethanol from agricultural lignocellulosics.