一株新的海洋放线菌所产黄色素稳定性研究及其16S rDNA序列分析

Study on stability of the yellow pigment from a new marine actinomycete and 16S rDNA analysis of the strain

对一株分离自威海海域的产黄色素的海洋放线菌新菌株MA01进行了色素提取方法及其稳定性的研究。测定其最大吸收波长,考察了pH、光照、温度、金属离子、氧化剂和还原剂、防腐剂等因素对黄色素稳定性的影响。此外,对菌株MA01进行分子鉴定,利用PCR技术扩增其16S rDNA序列,并构建了系统进化树。实验结果表明,该黄色素在300nm处有最大吸收峰,超声波法提取色素优于溶剂法。该黄色素为水溶性色素,易溶于甲醇和乙醇,在弱酸性、中性和碱性条件下稳定,温度小于60℃时热稳定性良好,对紫外光和可见光照射稳定性良好,基本不受金属离子K+、Na+、Mg2+、Mn2+、Ca2+影响,防腐剂食盐和蔗糖对其均无不良影响。该黄色素不耐氧化剂,还原剂也会降低其稳定性。16S rDNA序列分析和系统进化树显示菌株MA01与多株Streptomyces sp.的16S rDNA具有99%的相似性,初步鉴定菌株MA01是链霉菌属Streptomyces sp.的一种。菌株MA01具有较高的研究和开发价值。

Extraction conditions,basic properties and the stability of the yellow pigment produced by a new marine actinomycete strain MA01 ,which was isolated from Weihai sea area,were investigated in this paper. The maximum absorption wavelength was measured ,and the stability of the pigment was assessed under the conditions as following ：the different pH values,UV,fluoresnt lighting,the different temperatures,some kinds of ions,oxidant/reducer and preservatives. In addition,the 16S rDNA fragment of MA01 was amplified by PCR for molecular characterization,and the phylogenetic tree was constructed. Results showed that the maximum absorption wavelength of this yellow pigment was 300nm. The pigment was extracted better by ultrasonic extraction method than by solvent method. This yellow pigment was classified as a kind of water-soluble pigment,and is soluble in methanol and ethanol. Furthermore,it was stable at the temperature below 60℃ and under the neutral and alkaline conditions,but sensitive to oxidant,while had a good resistance to UV and light. Some metal ions（e.g. K＋,Na＋,Mg2＋,Mn2＋,Ca2＋） and common preservatives（e.g, salt and sucrose） did not affect the stability of the pigment. Phylogenetic tree analysis of 16S rDNA sequence indicated that the similarity between MA01 and multiple strains of Streptomyces sp.was higher than 99%. Therefore,MA01 was identified as a new strain belonging to Streptomyces sp. ,and had good value for research.