一种微生物发酵产蓝色素的稳定性及毒性研究

天然蓝色素十分罕见，直接采用微生物发酵并能用于食用的天然蓝色素至今未见报道。我们利用一株链霉菌（Ｓｔｒｏｐｔｏｍｙｃｅｓ）ＬＳ－１进行发酵，对其产生的蓝色素的稳定性、毒性进行了研究。实验结果表明本色素是蓝色粉末，几乎无臭无味，易溶于水和含水乙醇，在碱性时呈鲜明蓝色，在酸性时呈红色，耐热（８０～１００℃６０ｍｉｎ）不褪色，在ｐＨ＞７时光（包括紫外光）稳定性强，金属离子Ｎａ＋、Ｍｇ２＋对本色素无影响。本色素对革兰氏阴性细菌、酵母菌及丝状真菌无抑制作用，对革兰氏阳性细菌有微弱的拮抗作用。粗品毒性试验ＬＤ５０＞１５０００ｍｇ／ｋｇ，致突变试验阴性，色素粗品属无毒。发酵液色价吸光度（１０倍稀释水溶液）０．４（λｍａｘ＝５８１ｎｍ），发酵周期８０±２ｈ。研究结果认为本色素是一种很有开发前景的微生物天然蓝色素。

Studies on the Properties of a Microbial Blue Pigment

A blue pigment was obtained by a kind of microbial fermentation process. This pigment could dissolve in water or ethanol.Its thermostability was good. The pigment was red under acid conditions and blue when alkaline. Its photostability was good in neutral and alkaline. The metal ions such as Na ,Mg 2 didn't have effect on the pigment stability.The pigment didn't inhibit G - bacteria,yeast and filamentous fungi, but inhibited G bacteria slightly.The LD 50 of the pigment was higher than 15 000 mg/kg and belonged to non toxic range.It didn't lead to produce micronucleus of the human erythrocyte.The mutagenie experiment was negative.The experimental results showed that this pigment was a kind of good natural blue colorant having developmental perspective in food industry.