黑曲霉固态发酵生产单宁酶的条件优化

研究采用响应面法优化黑曲霉固态发酵生产单宁酶的培养条件。应用Plackett—Burman试验筛选出重要影响因子：五倍子粉含量、（NH4）2SO4浓度以及接种孢子量，最陡爬坡试验逼近最大响应区域。应用Box．Behnken响应面试验对重要影响因子进一步优化。得到最佳培养条件：每250mL三角瓶中装入1．0g五倍子粉、4．4g稻壳和0．5g麸皮、液固比（mL／g）2：1且营养盐溶液组成为（NH4）2s0421g/L、MgSO4·7H2O1g／L、NaCl1g／L，培养基pH自然，接种5．7×10^7个孢子后在30℃温度下培养4d。在此条件下，单宁酶产量从40U／g提高到114U／g，3次重复验证性试验平均值为115U／g，验证了模型的可靠性。

Optimization of tannase production by solid state fermentation from Aspergillus niger

Response surface methodology （RSM） was used to optimize culture conditions for tannase production by solid-state fermentation with Aspergillus niger. Plackett-Burman design （PBD） experiment screened out three significant factors：gallnut powder content, （NH4 ）2 SO4 concentration and spores number of inoculum. The steepest ascent experiment approached the greatest response space. Box- Behnken design （BBD） experiment was used to further optimize the significant factors. The optimum culture conditions for the production of tannase are as follows ： each 250 mL flask loaded 1.0 g gallnut powder,4. 4 g rice husk and 0.5 g wheat bran, liquid-solid ratio of the medium was 2： l and nutrient solution was constituted by （NH4）2SO4 21 g/L,MgSO4 ·7H2O1 g/L and NaC1 1 g/L,with a natural pH value ,the medium was inoculated with 5.7 ×10^7 spores and cultured under 30℃ for 4 days. Under those optimized culture conditions, the production of tannase increased from 40 U/g to 114 U/g. The reliability of the model was verified through triplicate experiments with an average yield of 115 U/g.