【摘要】 目的:选育产木聚糖酶活力高的黑曲霉菌株,对其产酶条件进行优化,并研究其酶学性质。方法:通过木聚糖酶解木聚糖产生透明圈的方法,筛选产木聚糖酶菌株,测定固体发酵培养基中玉米芯与麸皮的比例、培养温度、培养时间、添加氮源对产酶的影响。进行了作用温度、pH值、金属离子对酶活力的影响试验,以及酶不同温度下的热稳定性的试验。结果:从自然界筛选得到一株产木聚糖酶的黑曲霉菌株,通过对固态发酵培养条件优化,最终产酶水平达到了5500ug固体干曲。酶的最适作用温度是45℃、最适作用pH值4.8,是一种偏酸性酶。该酶在45℃以上的温度保存会使酶活力迅速丧失,Mg2+、Zn2+对该酶有激活作用,而Mn2+、Cu2+、Hg2+则完全抑制酶的活性。结论:选育的黑曲霉菌株产木聚糖酶活力较高,培养条件简单。更多还原

【Abstract】 Objectives:To selective breed Aspergillus niger for Xylanase production, and optimize it’s culturing condition, study it’s enzyme properties. Methods: Aspergillus niger producing Xylanase were picked out with transparence circle method. Effect of some factors as follows on enzyme production was studied: the ratio of corn cob to wheat bran, culturing temperature, culturing time, adding nitrogen sources. Effect of temperature, pH, metal ions on enzyme activity were tested. Enzyme stability in different temperature was tested.Results: An Aspergillus niger producing Xylanase was separated from nature soil. Cultivation conditions for the production of Xylanase in solid state were investigated. The Xylanase activity of the culture was 5500u/g dry koji. The optimal pH and temperature of the enzyme activity were 4.8 and 45℃. The activity of the enzyme was absent rapidly. above 45℃. The activity was activated by Mg~ 2+ and Zn 2+ and inhibited by Mn~ 2+ , Cu ~2+ and Hg~ 2+ . Conclusion: An Aspergillus niger producing Xylanase was screened. Its culture condition was simple.更多还原