Application of response surface methodology to the modeling of cellulase purification by solvent extraction

Central composite design (CCD)sp. JS14 in a solvent extraction was established with Response surface methodology (RSM). Solvent concentration, pH, temperature and retention time were selected as process variables to evaluate the purification impact factor in solvent precipitation, including the purification fold and % recovery. An experimental space with 13 purification fold and 23 recovery percentage recovery is achieved through the optimized condition based on the model. The molecular weight of the purified enzyme was estimated to be 32.5 KDa. Optimum activity of purified enzyme was at pH and temperature 6.5℃ and 40℃ respectively. Enzyme showed maximum activity with carboxymethyl cellulose as substrate with compare to rice husk, wheat straw and sucrose. The purified cellulase activity was inhibited by Na+, Cl- Mg2+ Tween 80 and EDTA.