水稻秸秆为原料的纤维素酶发酵条件优化
毕业论文关键词：纤文素酶、黑曲霉、发酵条件、正交试验
Optimization of cellulase fermentation conditions of rice straw as raw material
Abstract: The world is facing the increasing environmental pollution and oil crisis, More and more countries began using ethanol as a substitute fuel. China is an agricultural country, The energy problem can be solved by ethanol fermentation using crop straw, However, It’s ethanol yield is low and cost is high to produce ethanol using crop straw, So it’s important to improve the yield and reduce production cost. This paper is aimed at improving the activity of cellulose which can transform cellulose to fermentable sugar. This experiment is mainly through single factor and orthogonal experiment to study the effects of medium composition and culture conditions on cellulase production by Aspergillus niger, Mainly on water content, ratio of rice to flour, temperature, fermentation time, pH, ammonium sulfate, inoculation amount effect on the activity of cellulose. In order to obtain the optimal medium recipe: rice 2.4 g, soybean flour 0.6 g, water 70%, 4% (NH4)2SO4, 0.2% KH2PO4, 0.2% MgSO4, pH 7, inoculation 5×106. The optimal culture conditions: culture temperature 41℃, fermented for 6 days. Aspergillus niger cellulase production was increased from 374.89 U/g to 906.67 U/g through the optimization of cellulose fermentation conditions.
Keywords: cellulase, Aspergillus niger, fermentation conditions, orthogonal experiment
目录
引言 1
1.材料和方法 2
1.1材料 2
1.1.1菌种 2
1.1.2培养基 2
1.1.3试剂及配制 2
1.1.4仪器设备 2
1.2实验方法 2
1.2.1菌种复苏 2
1.2.2配制基础产酶培养基 3
1.2.3接种以及固体发酵 3
1.2.4葡萄糖标准曲线的制作 3
1.2.5粗酶液的制取 3
1.2.6酶活力的测定 3
1.2.7酶活力的计算 3
2.结果与分析 4
2.1葡萄糖标准曲线 4
2.2培养基及培养条件的优化结果 4
2.2.1水稻与豆粉比对产纤文素酶的影响 4
2.2.2硫酸铵对产纤文素酶的影响 5
2.2.3接种量对产纤文素酶的影响 6
2.2.4发酵天数对产纤文素酶的影响 6
2.2.5含水量对产纤文素酶的影响 7
2.2.6 pH值对产纤文素酶的影响 8
2.2.7温度对产纤文素酶的影响 8
2.3正交试验优化培养基 9
2.4正交试验结果与分析 9