天然黑色素发酵条件研究

生物工程论文编号:SW119  论文字数:12979,页数:28

目  录
中文摘要 I
英文摘要 II
目录 III
1  绪论 1
1.1  黑色素的分类及基本特征 1
1.2  黑色素的研究来源 2
1.3  黑色素的功能及应用领域 3
2  实验部分 6
2.1  实验材料 6
2.2  实验方法 6
2.3  黑色素发酵条件优化 7
2.4  黑色素标准曲线的绘制 8
2.5  黑色素理化性质的研究 8
3  结果与讨论 10
3.1  菌体的形态特征 10
3.2  黑色素发酵条件优化 10
3.3  黑色素标准曲线的绘制 15
3.4  黑色素理化性质研究 15
4  总结与展望 20
致  谢 21
参考文献 22

摘要：对宁夏沙漠中发现并分离纯化出的一种能产黑色素的菌株进行了菌落形态、菌体特征、生长培养基，黑色素的合成情况等进行了研究。结果表明在查氏培养基上，该菌株培养初期，菌丝体为白色，菌丝与培养基结合紧密，培养后期，菌丝体分泌大量黑色素，菌落形成皱褶。为了尽可能提高黑色的产量，对菌株的发酵条件进行了优化，结果表明最佳的发酵条件为：蔗糖 50 g/L，NaNO3 3 g/L，K2HPO4 •3H2O 1g∕L, KCl 0.5g∕L，MgSO4•7H2O 0.5g∕L，水1000ml。在28℃、转速为180 r/m的条件下培养，发酵液经粗提取后黑色素产量最高可达2.56g/L。在此基础上，对发酵得到的黑色素进行了理化性质的研究，结果表明该黑色素在紫外线照射下具有良好的稳定性，对还原剂具有良好的稳定性，有一定的抗氧化能力，但对高温、日光不太稳定。

关键词：黑色素；发酵；优化；理化性质

The study of fermentation conditions of the natural melanin

Abstract: This article study the colonial morphology, cell characteristics, growth medium, melanin synthesis of the melanin-producing strain which get from the desert in Ningxia. The results show that culture in czapek medium,the mycelium is white in early, mycelium combined with medium closely, culturing post,the mycelium secret a lot of melanin and the colony become fold. In order to improve the production of melanin as much as possible,the conditions of fermentation were optimized, the results show that the optimal fermentation conditions were: sucrose 50 g / L, NaNO3 3 g / L, K2HPO4·3H2O 1g / L, KCl 0.5g / L, MgSO4·7H2O 0.5g / L , water 1000ml.Culturing under the conditions of 28℃ and 180 r/m, crude extracts of melanin up to 2.56g/L. On this basis,studying the physical and chemical properties of melanin which carried out by the fermentation, the results show that the melanin has good stability under UV and good antiagent activity,it also has some antioxidant activity,but it is not very stable under high temperature and daylight.

Keywords：Melanin; fermentation; Optimization; physical and chemical properties