食品科学 ›› 2020, Vol. 41 ›› Issue (10): 172-179.doi: 10.7506/spkx1002-6630-20190314-184

• 生物工程 • 上一篇    下一篇

黑曲霉发酵产木糖苷酶工艺优化

汤勇,丁鸿皓,蔡俊   

  1. (湖北工业大学 发酵工程教育部重点实验室,工业微生物湖北省重点实验室,工业发酵湖北省协同创新中心,湖北 武汉 430068)
  • 收稿日期:2020-05-18 修回日期:2020-05-18 出版日期:2020-05-25 发布日期:2020-05-15

Optimization of Fermentation Conditions for Xylosidase Production by Aspergillus niger

TANG Yong, DING Honghao, CAI Jun   

  1. (Key Laboratory of Fermentation Engineering, Ministry of Education, Hubei Key Laboratory of Industrial Microbiology, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei University of Technology, Wuhan 430068, China)
  • Received:2020-05-18 Revised:2020-05-18 Online:2020-05-25 Published:2020-05-15

摘要: 为充分再利用玉米芯粉这种农副产品资源,以黑曲霉为菌种,进行黑曲霉液态发酵玉米芯粉产木糖苷酶的研究。首先采用单因素试验,以黑曲霉发酵过程中产生的木糖苷酶活力为响应值,考察发酵周期、发酵温度、接种量、初始发酵pH值、装液量和摇瓶转速对木糖苷酶活力的影响。结果表明:发酵时间144 h、发酵温度34 ℃、接种量7%、初始发酵pH 3.0、摇瓶转速180 r/min、装液量110 mL/300 mL为该菌产木糖苷酶的最佳发酵条件。然后在上述最佳发酵条件的基础上,结合Plackett-Burman试验、最低添加量试验、最陡爬坡试验和响应面中心组合试验确定了最佳产酶培养基组分为:玉米芯粉31.55 g/L,酵母粉8.00 g/L,蛋白胨5.48 g/L,硫酸镁0.70 g/L,氯化钠1.00 g/L,氯化钙1.50 g/L。利用软件构建二次式模型,模型决定系数R2为0.991 0,调整决定系数R2为0.982 9。回归方程的方差分析结果表明,模型显著有效,失拟项P值大于0.05,适用于产酶的理论预测。经过上述优化后菌株产木糖苷酶活力是优化前的8.89 倍。

关键词: 黑曲霉, 木糖苷酶, 发酵, 响应面法

Abstract: In order to fully utilize corn cob powder as an agricultural by-product, the submerged fermentation of Aspergillus niger using corn cob powder as a substrate was optimized for enhanced xylosidase activity. Firstly, one-factor-at-a-time method was used to investigate the effects of fermentation period, temperature, inoculum size, initial fermentation pH, medium volume and shaker speed on xylosidase activity. The results showed that a fermentation period of 144 h, a temperature of 34 ℃, an inoculum size of 7%, an initial fermentation pH of 3.0, a shaking speed of 180 r/min, and a medium volume of 110 mL in 300-mL shake flasks were found to be the best conditions. Further, using the Plackett-Burman design, lowest addition experiments, the steepest ascent method, and response surface methodology with central composite design, the optimal levels for medium components were determined as follows: corn kernel powder 31.55 g/L, yeast powder 8.00 g/L, peptone 5.48 g/L, magnesium sulfate 0.70 g/L, sodium chloride 1.00 g/L, and calcium chloride 1.50 g/L. A quadratic polynomial model was developed with a determination coefficient R2 of 0.991 0, and an adjustment coefficient R2 of 0.982 9. The analysis of variance (ANOVA) showed that the model was significant with a P value greater than 0.05 for lack-of-fit, supporting its use for the theoretical prediction of enzyme production. Under the optimized conditions, an 8.89-fold increase was observed in xylosidase activity of Aspergillus niger.

Key words: Aspergillus niger, xylosidase, fermentation, response surface methodology

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