Xu Yao-Xing, Li Yan-Li, Xu Shao-Chun, Liu Yong, Wang Xin, Tang Jiang-Wu
Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.
J Zhejiang Univ Sci B. 2008 Jul;9(7):558-66. doi: 10.1631/jzus.B0820038.
To study the optimal medium composition for xylanase production by Aspergillus niger XY-1 in solid-state fermentation (SSF).
Statistical methodology including the Plackett-Burman design (PBD) and the central composite design (CCD) was employed to investigate the individual crucial component of the medium that significantly affected the enzyme yield.
Firstly, NaNO(3), yeast extract, urea, Na(2)CO(3), MgSO(4), peptone and (NH(4))(2)SO(4) were screened as the significant factors positively affecting the xylanase production by PBD. Secondly, by valuating the nitrogen sources effect, urea was proved to be the most effective and economic nitrogen source for xylanase production and used for further optimization. Finally, the CCD and response surface methodology (RSM) were applied to determine the optimal concentration of each significant variable, which included urea, Na(2)CO(3) and MgSO(4). Subsequently a second-order polynomial was determined by multiple regression analysis. The optimum values of the critical components for maximum xylanase production were obtained as follows: x(1) (urea)=0.163 (41.63 g/L), x(2) (Na(2)CO(3))=-1.68 (2.64 g/L), x(3) (MgSO(4))=1.338 (10.68 g/L) and the predicted xylanase value was 14374.6 U/g dry substrate. Using the optimized condition, xylanase production by Aspergillus niger XY-1 after 48 h fermentation reached 14637 U/g dry substrate with wheat bran in the shake flask.
By using PBD and CCD, we obtained the optimal composition for xylanase production by Aspergillus niger XY-1 in SSF, and the results of no additional expensive medium and shortened fermentation time for higher xylanase production show the potential for industrial utilization.
研究黑曲霉XY - 1固态发酵生产木聚糖酶的最佳培养基组成。
采用包括Plackett - Burman设计（PBD）和中心复合设计（CCD）在内的统计方法，研究显著影响酶产量的培养基中各个关键成分。
首先，通过PBD筛选出NaNO₃、酵母提取物、尿素、Na₂CO₃、MgSO₄、蛋白胨和(NH₄)₂SO₄为对黑曲霉XY - 1生产木聚糖酶有显著正向影响的因素。其次，通过评估氮源效应，证明尿素是生产木聚糖酶最有效且经济的氮源，并用于进一步优化。最后，应用CCD和响应面方法（RSM）确定每个显著变量（包括尿素、Na₂CO₃和MgSO₄）的最佳浓度。随后通过多元回归分析确定二阶多项式。获得最大木聚糖酶产量的关键成分的最佳值如下：x(1)（尿素）=0.163（41.63 g/L），x(2)（Na₂CO₃）=-1.68（2.64 g/L），x(3)（MgSO₄）=1.338（10.68 g/L），预测的木聚糖酶值为14374.6 U/g干底物。在摇瓶中使用优化条件，黑曲霉XY - 1发酵48 h后用麦麸生产木聚糖酶的产量达到14637 U/g干底物。
通过使用PBD和CCD，我们获得了黑曲霉XY - 1固态发酵生产木聚糖酶的最佳组成，无需额外添加昂贵培养基且缩短发酵时间以提高木聚糖酶产量的结果显示了其工业利用潜力。
