固定化细胞生产黑色素的研究

STUDIES ON PRODUCTION OF MELANIN SYNTHESIZED BY IMMOBILIZED CELLS

利用固定化产酪氨酸酶的假单胞菌（Ｐｓｅｕｄｏｍｏｎａｓｓｐ．）以酪氨酸为底物生产黑色素．该黑色素的紫外扫描光谱图显示随波长的减小其吸收值增大，在２１０ｎｍ处有一吸收峰；红外光谱显示它在３μｍ和６μｍ处有吸收峰，从而证实它是一种黑色素．固定化细胞摇瓶半连续发酵产黑色素结果表明，最适温度为３７℃，最适ｐＨ为９．５．加入微量铜离子、供氧良好和较低的底物加入量有利于黑色素的生成．在生理盐水中低温振荡处理可提高操作稳定性，使重复利用次数达到９次。

A kind of melanin was synthesized from L tyrosine by the tyrosinase producing immobilized bacteria(P.maltophilia 135). The ultraviolet visible absorption spectrum of the melanin showed a steadily increasing absorption ranging from 600 nm to 210 nm with a peak at about 210 nm. In the infra red spectrum of the melanin, there were characteristic absorption at about 3 μm and 6 μm. The above results verified that the product we had got was indeed a kind of melanin. The shake culture results showed a temperature optimum of 30 degree C and a pH optimum of 9.5. Traces of cupric ions, plenty of oxygen supply and less L tyrosine addition were favorable for melanin synthesis.The immobilized cells shaken in the physiological saline exhibited higher operational stabilities, in which the immobilized cells can be used 9 times repeatedly with 180 hours.