一株产棕色素放线菌的分离鉴定及其色素性质

Identification of an Actinomyces Producing Natural Brown Pigment and Detection of Pigment Stability

从太白山汤峪国家森林公园土壤样品中分离到1株产棕色素的放线菌菌株A-3。该菌株在高氏Ⅰ号培养基上可产生水溶性棕色素,镜检气生菌丝灰白色、呈分枝状,孢子丝直,孢子成链、呈柱状。结合菌落形态及培养特征,初步鉴定菌株A-3属链霉菌属灰褐类群。16SrDNA序列分析显示,该菌株与Streptomycesalbospreus,Streptomyces cavourensis等同源性较高。邻接法构建系统发育树后,菌株A-3与S.cavourensis聚在一类。对水溶性、棕色素的最大吸收波长,NaCl、蔗糖、温度、pH和O2等因素对色素稳定性的影响进行探讨。

An actinomyces strain A-3 was isolated from the soil of Taibai Mountain National Forest Park. The strain could produce a water soluble brown pigment when it was cultured on Gause＇s synthetic agar medium. Morphological observation showed that the strain had grey white and branched aerial hypha and straight chain of cylindrical spores. It could be primarily identified that the strain A- 3 belongs to griseofuscus group of the genus Streptomyces according to its morphological and cultural characteristics. Analysis of the 16S rDNA gene sequence of the strain A-3 revealed that it shared the highest similarity with Streptomyces albospreus and Streptomyces cavourensis, etc. The phylogenetic tree derived with Neighbor-joining method showed that the strain A-3 was clustered with S. cavou- rensis. Furthermore, the characterization of the brown pigment was also studied. The analysis of light absorption, chemical analysis of different factors like NaCl, sucrose, temperature, pH and O2 on the pigment stability revealed that the pigment had a potential value as food additive.