(15h) Flux Enhancement in Recycling Cellulase From Enzymatic Hydrolyzate of Acid Treated Wheat Straw by Electroultrafiltration

Ultrafiltration has been applied extensively in concentration and separation of biomacromolecules. It also shows great potential in recovering both cellulase and β-glucosidase from lignocellulosic hydrolyzates by one step without addition of any chemical. In addition, ultrafiltration membrane reactor coupled with microfiltration or not, could recycle cellulase while removing end-products continuously during hydrolysis. In spite of these advantages, fouling and concentration polarization, which cause flux decline limiting application of membrane processes significantly, are two severe problems remaining to be resolved. In the present work, to enhance the membrane filtration performance in recycling cellulase from lignocellulosic hydrolyzate by ultrafiltration, an electric field was applied across the membrane. The feasibility of electroultrafiltration (EUF) to recycle cellulase was first determined by measuring the filter paper activity of cellulase after EUF of cellulase solution, and the effect of electric field under different operating conditions (molar concentration of buffer, acid treated wheat straw concentration, current and temperature) on permeate flux during  EUF was examined indetail. The results showed that EUF was an effective method to recycle cellulase due to its high cellulase activity recovery and high flux. Under appropriate operating conditions, the fllux for 2% (substrate concentration, w/v) lignocellulosic hydrolyzate increased by a factor of 5.0 when an electric strength of 920 V/m was applied, compared to that without electric field. The improvement of flux was independent on substrate concentration. Therefore, EUF could be a useful approach to recycle cellulase for reducing hydrolysis cost.