黑曲霉产纤维素酶混合发酵条件的研究

为选出高产纤维素酶菌株，对不同菌株进行筛选，通过4种纤维素酶活力大小比较单一菌株与混合菌株的产酶能力。利用3,5-二硝基水杨酸（DNS）法测定各单一菌株及混合菌株的内切葡聚糖酶活、滤纸酶活、外切葡聚糖酶活和β-葡萄糖苷酶活，筛选最优组合，在单因素试验的基础上通过响应面试验确定最佳产酶条件。结果表明，混合菌最佳产酶条件：混合菌株D2∶D2-1=2∶1，发酵时间6 d，接种量6%，发酵温度28 ℃。优化后滤纸酶活力达到156.26 U/mL，较优化前的滤纸酶活（113.96 U/mL）提高了37.1%。

Multi-strains fermentation condition of Aspergillus niger for cellulase production

In order to screen the strain with high yield cellulase, the cellulase-producing ability of single strain and multi-strains was compared through four kinds of cellulase activity. DNS method was used to determine endoglucanase activity, filter paper enzyme activity, exoglucanases activity and beta-glycosidase activity of each single strain and multi-strains, to screen the optimal multi-strains. On the basis of single factor experiment, the optimal cellulase-producing condition was optimized by response surface methodology. The results showed that the optimal condition was strain D2∶D2-1=2∶1, fermentation time 6 d, inoculum 6% and temperature 28 ℃. After optimization, the filter paper enzyme activity can reach 156.26 U/ml, which was 37.1% higher than that before optimization (113.96 U/ml).