RESPONSE SURFACE METHODOLOGICAL OPTIMIZATION OF THE MEDIUM COMPONENTS FOR PRODUCTION OF XYLANASE UNDER SSF BY ASPERGILLUS FUMIGATUS

Abstract

Response surface methodology was employed for the optimization of various medium components for the production of xylanase by Aspergillus fumigatus in solid state fermentation. The medium components influencing the enzyme production were screeened using Plackett-Burman design. Among the twelve independent variables screened by using Plackett-Burman design, only four variables FeSO4.7H2O, Yeast extract, KH2PO4 and CoSO4 were found to be significantly affecting variable for xylanase production. For obtaining the mutual interaction between the four variables and optimizing these variables, a 23 factorial central composite design (CCD) using response surface methodology was employed. The optimal values of four variables obtained for maximal production of xylanase were: FeSO4.7H2O - 8.0817 mg/gds, yeast extract - 35.057 mg/gds, KH2PO4 - 21.700 mg/gds and CoSO4 – 3.1717 mg/gds with a predicted xylanase activity of 354.33 IU/gds. These predicted optimal parameters were tested by carrying out the three repeated batch experiments in the laboratory and the maximum xylanase activity (355 IU/gds) obtained was close to the predicted value. A poor quantity of carboxy methyl cellulase activity was also obtained in all the experimental runs.