考氏科萨克氏菌产阿魏酸酯酶条件优化、酶学性质及其初步应用

以考氏科萨克氏菌（Kosakonia cowanii）为试验菌株，对其产酶条件、酶活性质以及初步应用进行研究。结果表明，最佳产酶条件为装液量90 mL/250 mL、培养基初始pH值为5.5、接种量4%、温度34 ℃。在此优化条件下，酶活为28.27 U/L，比优化前提高了20.92%。该酶最适反应温度、pH值分别为 50 ℃、5.6，在30～40 ℃及pH 5.0～6.8范围内稳定性良好。将该菌株应用到麸皮、大曲和糟醅中，麸皮中发酵至第7天时阿魏酸含量比最初提高了22.42%，糟醅中阿魏酸含量呈先增后减趋势，大曲中阿魏酸含量呈递增趋势，表明添加菌株有利于释放麸皮、糟醅和大曲中的阿魏酸。

Optimization of feruloyl esterase production condition by Kosakonia cowanii,enzymatic propertyand preliminary application

Using Kosakonia cowanii as the experimental strain, the enzyme production conditions, enzymatic properties and preliminary application of the strain were studied. The results showed that the optimal enzyme production conditions were liquid medium volume 90 ml/250 ml, initial medium pH 5.5,inoculum 4%, and temperature 34 ℃. Under the optimal conditions, the enzyme activity was 28.27 U/L, which was 20.92% higher than that before the optimization. The optimum reaction temperature and pH value of the enzyme were 50 ℃ and 5.6, respectively, with good stability in the range of 30-40 ℃and pH 5.0-6.8. When the strain was applied to wheat bran, Daqu and distilled grains, the ferulic acid content in wheat bran in the 7 th day of fermentation was 22.42% higher than that in the initial stage. The ferulic acid content in distilled grains increased first and then decreased. The ferulic acid content in Daqu showed an increasing trend, indicating that the addition of strain was beneficial to the release of ferulic acid in wheat bran, Daqu and distilled grains.