一株新分離微生物合成天然色素研究

生物工程論文編號:SW145  論文字數:13547,頁數:31

目 錄
中文摘要 I
英文摘要 II
目錄 III
1  緒論 1
1.1  微生物物礦化資源研究 1
1.2  微生物產油的研究 3
1.3  黑色素的研究 4
2  實驗部分 6
2.1  實驗材料 6
2.2  菌種的篩選 7
2.3  色素標準曲線 7
2.4  菌體生長與產色素量的關系 7
2.5  菌絲體油脂的測定 7
2.6  菌體C、N源的利用實驗 8
2.7  產黑色素菌株的發酵條件優化 8
2.8  黑色素的純化 9
2.9  黑色素的理化性質 9
2.10  黑色素穩定性研究 9
3  結果和討論 11
3.1  菌種的分離純化 11
3.2  黑色素的標準曲線 12
3.3 菌體的生長與產色素量的關系 12
3.4  菌絲體油脂的含量 13
3.5  菌體C、N源的利用實驗 14
3.6  產黑色素菌株的發酵條件優化 15
3.7  純化的黑色素固體 17
3.8  黑色素的理化性質 18
3.9  黑色素穩定性研究 20
4 總結與展望 24
致謝 25
參考文獻 26

摘 要：在寧夏沙漠地帶發現一種由微生物生長而凝結成的沙土管，對該沙土管中的微生物進行篩選，篩選得到一株在生長過程能產黑色素的微生物純培養。并對其菌絲形態、積累油脂性能、生長情況、色素合成情況等進行研究。為了提高菌株的產色素能力，對菌株的發酵條件進行了優化，結果表明最佳條件為：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℃、轉速為200 r/m，在此條件下，黑色素產量達到3.63 g/L，是初始發酵條件下的1.47倍。將發酵生產的色素提純后，低溫烘干得到黑色固體粉末狀，在200-800nm波長范圍內進行紫外-可見光掃描，發現該色素的最大吸收波為415nm。該色素易溶于堿溶液（pH11），微溶于甲醇、氯仿和堿溶液（pH8），但是難溶于乙醚、水和酸溶液。 最后，對菌株所產的黑色素穩定性進行了初步研究，結果表明該黑色素在高溫和紫外線照射下，具有良好的穩定性；但是在長時間陽光直射下，其穩定性下降；同時隨著pH值的升高，該黑色素的溶解性不斷升高，在pH為1-2時可以產生沉淀，在酸的條件下，黑色素基本上不溶解，到pH8以后黑色素開始溶解，隨著pH值的升高，黑色素的溶解性更好。此菌株所產黑色素還具有良好的耐氧化性和還原性。
關鍵詞：黑色素；發酵條件；優化；穩定性

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