OPTIMIZATION OF HYDROLYSIS CONDITIONS OF WHEAT STRAW BY ENZYME PREPARATION FROM Fennellia sp. 2806

The aim of the work was to optimize the hydrolysis conditions of wheat straw by complex enzyme preparation from Fennellia sp. 2806 with endo-, exoglucanase, xylanase and β-glucosidase activities. Bioconversion of wheat straw was carried out by an enzyme preparation obtained from the culture filtrate of Fennellia sp. 2806. The two methods of statistical optimization of the experiment — the Plackett-Burman (determination of significant factors) and Box-Behnken (determination of optimal values of defined significant factors) methods were used consequentially to optimize the hydrolysis conditions. Endo-, exoglucanase, xylanase and β-glucosidase activities were assayed in enzyme preparation. Reducing sugars were determined by the modified Bertrand method. As a result of two-stage optimization of the bioconversion process of wheat straw by enzyme preparation from Fennellia sp. 2806, it was found that the highest reducing sugars values were formed at temperature 50 ºC, pH 5.0, substrate concentration 100 mg/ml, endoglucanase activity — 0.012 u/mg substrate, process duration — 18 h and pre-treatment by 4.5% alkali solution with further exposure to a microwave irradiation 6 W/g WS for 10 min. So it was established that temperature, pH, substrate concentration, pre-treatment of wheat straw by alkali solution and microwave irradiation were the significant factors for the hydrolysis process of substrate by enzyme preparation from Fennellia sp. 2806. Reducing sugars concentration was increased 1.5–2.0 times compared with the results obtained for the native wheat straw.