一株铁皮石斛内生真菌的色素稳定性研究

本研究以铁皮石斛体内分离筛选得到一株产橙红色色素的内生真菌X1为研究对象,为明确该菌株的种属及其所产天然色素的稳定性,采用分子生物学的方法,鉴定该菌株归属于Neurospora sp.一种。该菌株所产橙色素在400 nm波长处有最大吸收峰;从温度、pH、光照、氧化剂与还原剂四个单因子,对该株菌进行色素稳定性研究。结果表明该色素在紫外光下放置6 h橙色素光吸收值增大,说明有增色效应;在pH 2～8,20～100℃下不受太大影响;H_20_2和Na_2SO_3对该色素有较强的破坏力;Fe³⁺、Zn²⁺、Cu²⁺、Ca²⁺和Mn²⁺对该色素具有保色或增色作用;10%NaCl和15%葡萄糖溶液对色素均有增色效应。该研究对内生真菌分离及真菌色素提取工艺具有一定的理论指导意义。

Study on the stability of pigments produced by endnophytic fungi from Dendrobium candidum

In this study,an endophytic fungi X1 that produces orange pigment was isolated and screened out from Dendrobium candidum. In order to clarify the species of this strain and the stability of its natural pigments,and the strain was identified as Neurospora sp. based on molecular biology. The orange pigment which produced at this strain has the highest absorption peak at 400nm. It is show that when the pigment is placed in ultraviolet light for 6 h,the absorption value increased,indicating a color enhancement effect. It is not affected much at pH 2-8 and 20-100 ℃. Furthermore,H2O2 and Na2 SO3 have strong de- structive power to the pigment though several common additives have no effect on the pigment. In the metalions,Fe^3+,Zn^2+, Cu^2+,Ca^2+ and Mn^2+ have color protection or burnish effect on the pigment. Meanwhile ,10% NaCl and 15% glucose solution also have a significant hyperchromic effect on it. This study has theoretical and practical importance for the separation of en- dophytic fungi and extraction process of fungal pigments.