一株新分离微生物合成天然色素研究

文档编号:SW145  文档字数:13547,页数:31

摘 要：在宁夏沙漠地带发现一种由微生物生长而凝结成的沙土管，对该沙土管中的微生物进行筛选，筛选得到一株在生长过程能产黑色素的微生物纯培养。并对其菌丝形态、积累油脂性能、生长情况、色素合成情况等进行研究。为了提高菌株的产色素能力，对菌株的发酵条件进行了优化，结果表明最佳条件为：玉米粉30 g/L、蛋白胨1 g/L、L-酪氨酸2.5 g/L，pH 8.0，在30℃、转速为200 r/m，在此条件下，黑色素产量达到3.63 g/L，是初始发酵条件下的1.47倍。将发酵生产的色素提纯后，低温烘干得到黑色固体粉末状，在200-800nm波长范围内进行紫外-可见光扫描，发现该色素的最大吸收波为415nm。该色素易溶于碱溶液（pH11），微溶于甲醇、氯仿和碱溶液（pH8），但是难溶于乙醚、水和酸溶液。 最后，对菌株所产的黑色素稳定性进行了初步研究，结果表明该黑色素在高温和紫外线照射下，具有良好的稳定性；但是在长时间阳光直射下，其稳定性下降；同时随着pH值的升高，该黑色素的溶解性不断升高，在pH为1-2时可以产生沉淀，在酸的条件下，黑色素基本上不溶解，到pH8以后黑色素开始溶解，随着pH值的升高，黑色素的溶解性更好。此菌株所产黑色素还具有良好的耐氧化性和还原性。
关键词：黑色素；发酵条件；优化；稳定性

Research on the synthesis of melanin from a new strain

Abstract：Our district that is in the desert in Ningxia discovers that a species may be a new microorganism, so carry on separating the early of the purification plate and picking a single colony to the germ species to grow with the purification germ. And to its mycelial morphology, the accumulation fat performance, the growth situation, the pigment synthesis situation and so on conducts the research.To improve the melanin′s product of the Strain, the fermention condition and medium of the Strain  were optimized. The result indicates that the most suitable medium is: corn meal 30g/L、peptone 1g/L、L-tyr 2.5g/L,pH 8.0,At 30℃ and 200 r/m,the output of melanin reaches 3.63 g/L which is 1.47 times of the output under the primary ferment condition. Production of the pigment will be purified, low-temperature drying be solid black powder, in the 200-800 nm wavelength ultraviolet within - visible light scanning, the pigments absorb the largest wave of 415 nm, soluble in alkaline solution (pH11), Slightly soluble methanol, chloroform and alkali solution (pH8), but difficult to dissolve ether, water and acid. Finally, the strain produced by the stability of melanoma conducted a preliminary study results show that the melanin in the heat, and ultraviolet radiation, has a good stability, but in the long period of time under direct sunlight, the stability of decline as in pH value increased, the solubility of the rising melanoma, the pH of 1-2, can produce precipitation in acid conditions, the melanoma basically do not dissolved after the melanoma started to pH8 solution, with pH values or the , The solubility of melanoma better. This strain produced by melanin also has good resistance to oxidation and reductive.
Keywords：melanin; Fermentation Conditions; optimization; stability

目 录
中文摘要 I
英文摘要 II
目录 III
1  绪论 1
1.1  微生物物矿化资源研究 1
1.2  微生物产油的研究 3
1.3  黑色素的研究 4
2  实验部分 6
2.1  实验材料 6
2.2  菌种的筛选 7
2.3  色素标准曲线 7
2.4  菌体生长与产色素量的关系 7
2.5  菌丝体油脂的测定 7
2.6  菌体C、N源的利用实验 8
2.7  产黑色素菌株的发酵条件优化 8
2.8  黑色素的纯化 9
2.9  黑色素的理化性质 9
2.10  黑色素稳定性研究 9
3  结果和讨论 11
3.1  菌种的分离纯化 11
3.2  黑色素的标准曲线 12
3.3 菌体的生长与产色素量的关系 12
3.4  菌丝体油脂的含量 13
3.5  菌体C、N源的利用实验 14
3.6  产黑色素菌株的发酵条件优化 15
3.7  纯化的黑色素固体 17
3.8  黑色素的理化性质 18
3.9  黑色素稳定性研究 20
4 总结与展望 24
致谢 25
参考文献 26

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