title: [Fermentation optimization by response surface methodology for enhanced production of beta-glucosidase of Aspergillus niger HDF05].
abstract: In order to obtain high beta-glucosidase productivity, we optimized the fermentation parameters for beta-glucosidase production by Aspergillus niger HDF05. First, we screened the important parameters by Plackeet-Burman design. Second, we used the path of steepest ascent to approach to the biggest response region of parameters affecting beta-glucosidase production. Then, we obtained the optimal parameters by central composite design and response surface analysis. We developed a quadratic polynomial equation for predicting beta-glucosidase production level. The results showed that the important parameters were temperature, packing volume, concentrations of wheat bran and (NH4)2SO4. The optimal fermentation parameters were as follows: temperature 28 degrees C, packing volume 71.4 mL/250 mL, wheat bran 36 g/L and (NH4)2SO4 5.5 g/L. Under the optimal conditions, we obtained the maximum enzyme activity of 60.06 U/mL, with an increase of 23.9% compared to the original fermentation parameters. During enzymatic hydrolysis of acid-pretreated corncob, addition of beta-glucosidase from Aspergillus niger HDF05 greatly reduced the inhibition caused by cellobiose, and the hydrolysis yield was improved from 66.7% to 80.4%.
authors.affiliation: College of Resource and Environment, Northeast Agricultural University, Harbin 150030, China.
authors.forename: Hongzhi
authors.initials: H
authors.lastname: Ling
authors.forename: Jingping
authors.initials: J
authors.lastname: Ge
authors.forename: Wenxiang
authors.initials: W
authors.lastname: Ping
authors.forename: Xiuhong
authors.initials: X
authors.lastname: Xu
mesh_terms: D000645:Ammonium Sulfate / Q000494:pharmacology; D001234:Aspergillus niger / Q000201:enzymology* / Q000254:growth & development; D046508:Culture Techniques / Q000379:methods; D005285:Fermentation; D007218:Industrial Microbiology; D013696:Temperature; D001617:beta-Glucosidase / Q000096:biosynthesis*
chemical_list: D001617:beta-Glucosidase; D000645:Ammonium Sulfate